Amino acid compounds and methods of use

ABSTRACT

or a salt thereof, wherein R1, G, L1, L2, L3, and Y are as described herein. Compounds of formula (I) and pharmaceutical compositions thereof are inhibitors of one, or both of, αvβ1 integrin and αvβ6 integrin that are useful for treating fibrosis such as in nonalcoholic steatohepatitis (NASH), idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP).

RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Pat. App. No. 62/742,901, filed Oct. 8, 2018, the entire contents of which are incorporated by reference herein.

FIELD OF THE INVENTION

This disclosure relates generally to therapeutic agents that may be useful as αvβ6 integrin inhibitors. The therapeutic agents may be used in the treatment or prophylactic treatment of fibrosis such as idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP).

BACKGROUND

Fibrosis, a pathologic feature of many diseases, is caused by a dysfunction in the body's natural ability to repair damaged tissues. If left untreated, fibrosis can result in scarring of vital organs causing irreparable damage and eventual organ failure.

Patients with nonalcoholic fatty liver disease (NAFLD) may progress from simple steatosis to nonalcoholic steatohepatitis (NASH) and then fibrosis. While liver fibrosis is reversible in its initial stages, progressive liver fibrosis can lead to cirrhosis.

Fibrosis in the kidney, characterized by glomerulosclerosis and tubulointerstitial fibrosis, is the final common manifestation of a wide variety of chronic kidney diseases (CKD). Irrespective of the initial causes, progressive CKD often results in widespread tissue scarring that leads to destruction of kidney parenchyma and end-stage renal failure, a devastating condition that requires dialysis or kidney replacement.

Scleroderma encompasses a spectrum of complex and variable conditions primarily characterized by fibrosis, vascular alterations, and autoimmunity. The scleroderma spectrum of disorders share the common feature of fibrosis, resulting in hardening or thickening of the skin. For some patients, this hardening occurs only in limited areas, but for others, it can spread to other major organs.

Following myocardial infarction, cardiac structural remodeling is associated with an inflammatory reaction, resulting in scar formation at the site of the infarction. This scar formation is a result of fibrotic tissue deposition which may lead to reduced cardiac function and disruption of electrical activity within the heart.

Crohn's Disease is a chronic disease of unknown etiology tending to progress even in the setting of medical or surgical treatment. Intestinal fibrosis is among the most common complications of Crohn's disease, resulting in stricture formation in the small intestine and colon.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing disease of unknown etiology, occurring in adults and limited to the lungs. In IPF, the lung tissue becomes thickened, stiff, and scarred. As lung fibrosis progresses, it becomes more difficult for the lungs to transfer oxygen into the bloodstream and the organs do not receive the oxygen needed to function properly. IPF currently affects approximately 200,000 people in the U.S., resulting in 40,000 deaths per year. Patients diagnosed with IPF experience progressive breathlessness and eventually, complete respiratory failure.

Primary biliary cholangitis (PBC), also known as primary biliary cirrhosis, is a chronic disease of the liver that causes damage and fibrosis in the liver. It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to build up in the liver, a condition called cholestasis. Over time, this leads to scarring and fibrosis in both the liver and biliary tract.

Nonspecific interstitial pneumonia (NSIP) is a rare disorder that affects the tissue that surrounds and separates the tiny air sacs of the lungs. These air sacs, called the alveoli, are where the exchange of oxygen and carbon dioxide takes place between the lungs and the bloodstream. Interstitial pneumonia is a disease in which the mesh-like walls of the alveoli become inflamed. The pleura (a thin covering that protects and cushions the lungs and the individual lobes of the lungs) might become inflamed as well. There are two primary forms of NSIP—cellular and fibrotic. The cellular form is defined mainly by inflammation of the cells of the interstitium. The fibrotic form is defined by thickening and scarring of lung tissue. This scarring is known as fibrosis and is irreversible. When the lung tissue thickens or becomes scarred, it does not function as effectively. Breathing becomes less efficient, and there are lower levels of oxygen in the blood. (Kim et al., Proc. Am. Thorac. Soc. (2006) 3:285-292; Lynch, D., Radiology (2001) 221:583-584; Kinder et al., Am. J. Respir. Crit. Care Med. (2007) 176:691-697)

Available courses of treatment are scarce, as there are currently no options on the market proven to have an effect on long-term patient survival or symptomatology. There remains a need for treatment of fibrotic diseases.

The αvβ6 integrin is expressed in epithelial cells, and binds to the latency-associated peptide of transforming growth factor-β1 (TGFβ1) and mediates TGFβ1 activation. Its expression level is significantly increased after injury to lung and cholangiocytes, and plays a critical in vivo role in tissue fibrosis. Increased levels are also associated with increased mortality in IPF and NSIP patients.

Primary sclerosing cholangitis (PSC) involves bile duct inflammation, and fibrosis that obliterates the bile ducts. The resulting impediment to the flow of bile to the intestines can lead to cirrhosis of the liver and subsequent complications such as liver failure and liver cancer. Expression of αvβ6 is elevated in liver and bile duct of PSC patients.

The present disclosure provides for αvβ6 integrin inhibitors that may be useful for treatment of fibrosis.

SUMMARY

Disclosed are amino acid compounds that are αvβ6 integrin inhibitors, compositions containing these compounds and methods for treating diseases mediated by αvβ6 integrin such as a fibrotic disease.

In one aspect, provided is a compound of formula (I), or any variation thereof, or a salt thereof (e.g., a pharmaceutically acceptable salt thereof), as detailed herein.

Further provided is a pharmaceutical composition comprising a compound of formula (I), or any variation thereof detailed herein, or a salt thereof (e.g., a pharmaceutically acceptable salt thereof), and a pharmaceutically acceptable carrier or excipient.

In another aspect, provided is a method of treating a fibrotic disease or condition in an individual (such as a human) in need thereof comprising administering to the individual a therapeutically effective amount of a compound of formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof. In some embodiments, the fibrotic disease or condition is pulmonary, liver, renal, cardiac, dermal, or gastrointestinal fibrosis. In other embodiments the fibrotic disease or condition is idiopathic pulmonary fibrosis, interstitial lung disease, radiation-induced pulmonary fibrosis, nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), alcoholic liver disease induced fibrosis, Alport syndrome, primary sclerosing cholangitis, primarily biliary cholangitis (also known as primary biliary cirrhosis), systemic sclerosis associated interstitial lung disease, scleroderma (also known as systemic sclerosis), diabetic nephropathy, diabetic kidney disease, focal segmental glomerulosclerosis, chronic kidney disease, and Crohn's Disease.

In another aspect, provided is a method of delaying the onset and/or development of a fibrotic disease or condition in an individual (such as a human) who is at risk for developing a fibrotic disease or condition comprising administering to the individual a therapeutically effective amount of a compound of formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof. In some embodiments, the disease or condition is pulmonary, liver, renal, cardiac, dermal, or gastrointestinal fibrosis. In other embodiments the fibrotic disease or condition is idiopathic pulmonary fibrosis, interstitial lung disease, radiation-induced pulmonary fibrosis, nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), alcoholic liver disease induced fibrosis, Alport syndrome, primary sclerosing cholangitis, primarily biliary cholangitis (also known as primary biliary cirrhosis), systemic sclerosis associated interstitial lung disease, scleroderma (also known as systemic sclerosis), diabetic nephropathy, diabetic kidney disease, focal segmental glomerulosclerosis, chronic kidney disease, and Crohn's Disease.

Also provided is a compound of formula (I), or any variation thereof detailed herein, or a pharmaceutical composition thereof, for the treatment of a fibrotic disease.

Also provided is use of a compound of formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for the treatment of a fibrotic disease.

Further provided is a kit comprising a compound of formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof. In some embodiments, the kit comprises instructions for use according to a method described herein, such as a method of treating a fibrotic disease in an individual.

In another aspect, provided is a method of making a compound of formula (I) or any variation thereof. Also provided are compound intermediates useful in synthesis of a compound of formula (I), or any variation thereof.

It is understood that aspects and variations described herein also include “consisting” and/or “consisting essentially of” aspects and variations.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1, Table 2 shows chemical structures for various compounds disclosed herein. Reference to compound numbers in the table in some instances depicts a particular stereoisomeric form of the compound number, as will be evident from the chemical structure depicted.

FIG. 2, Table B-2 shows biological data for various compounds disclosed herein.

DETAILED DESCRIPTION

The invention provides, inter alia, compounds of formula (I), and variations thereof, pharmaceutical compositions comprising compounds of formula (I), and methods of using such compounds and compositions in treating fibrotic diseases. Compounds and pharmaceutical compositions comprising salts of compounds of formula (I) are provided as well.

Definitions

For use herein, unless clearly indicated otherwise, use of the terms “a”, “an” and the like refers to one or more.

Reference to “about” a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se. For example, description referring to “about X” includes description of “X”. Likewise, reference to a value “X” also includes description of “about X”.

“Alkyl” as used herein refers to and includes, unless otherwise stated, a saturated linear (i.e., unbranched) or branched univalent hydrocarbon chain or combination thereof, having the number of carbon atoms designated (i.e., C₁-C₁₀ means one to ten carbon atoms). Particular alkyl groups are those having 1 to 20 carbon atoms (a “C₁-C₂₀ alkyl”), having 1 to 10 carbon atoms (a “C₁-C₁₀ alkyl”), having 6 to 10 carbon atoms (a “C₆-C₁₀ alkyl”), having 1 to 6 carbon atoms (a “C₁-C₆ alkyl”), having 2 to 6 carbon atoms (a “C₂-C₆ alkyl”), or having 1 to 4 carbon atoms (a “C₁-C₄ alkyl”). Examples of alkyl groups include, but are not limited to, groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, and the like.

“Alkylene” as used herein refers to the same residues as alkyl, but having bivalency. Particular alkylene groups are those having 1 to 20 carbon atoms (a “C₁-C₂₀ alkylene”), having 1 to 10 carbon atoms (a “C₁-C₁₀ alkylene”), having 6 to 10 carbon atoms (a “C₆-C₁₀ alkylene”), having 1 to 6 carbon atoms (a “C₁-C₆ alkylene”), 1 to 5 carbon atoms (a “C₁-C₅ alkylene”), 1 to 4 carbon atoms (a “C₁-C₄ alkylene”) or 1 to 3 carbon atoms (a “C₁-C₃ alkylene”). Examples of alkylene include, but are not limited to, groups such as methylene (—CH₂—), ethylene (—CH₂CH₂—), propylene (—CH₂CH₂CH₂—), isopropylene (—CH₂CH(CH₃)—), butylene (—CH₂(CH₂)₂CH₂—), isobutylene (—CH₂CH(CH₃)CH₂—), pentylene (—CH₂(CH₂)₃CH₂—), hexylene (—CH₂(CH₂)₄CH₂—), heptylene (—CH₂(CH₂)₅CH₂—), octylene (—CH₂(CH₂)₆CH₂—), and the like. It is understood that when alkylene is substituted (for example with a cycloalkyl group), the substituent is not one of the sites of bivalency. For example, propylene substitution with cyclopropyl may provide

but does not provide

wherein the wavy line denotes a site of bivalency.

“Alkenyl” as used herein refers to and includes, unless otherwise stated, an unsaturated linear (i.e., unbranched) or branched univalent hydrocarbon chain or combination thereof, having at least one site of olefinic unsaturation (i.e., having at least one moiety of the formula C═C) and having the number of carbon atoms designated (i.e., C₂-C₁₀ means two to ten carbon atoms). An alkenyl group may have “cis” or “trans” configurations, or alternatively have “E” or “Z” configurations. Particular alkenyl groups are those having 2 to 20 carbon atoms (a “C₂-C₂₀ alkenyl”), having 6 to 10 carbon atoms (a “C₆-C₁₀ alkenyl”), having 2 to 8 carbon atoms (a “C₂-C₈ alkenyl”), having 2 to 6 carbon atoms (a “C₂-C₆ alkenyl”), or having 2 to 4 carbon atoms (a “C₂-C₄ alkenyl”). Examples of alkenyl groups include, but are not limited to, groups such as ethenyl (or vinyl), prop-1-enyl, prop-2-enyl (or allyl), 2-methylprop-1-enyl, but-1-enyl, but-2-enyl, but-3-enyl, buta-1,3-dienyl, 2-methylbuta-1,3-dienyl, pent-1-enyl, pent-2-enyl, hex-1-enyl, hex-2-enyl, hex-3-enyl, and the like.

“Alkenylene” as used herein refers to the same residues as alkenyl, but having bivalency. Particular alkenylene groups are those having 2 to 20 carbon atoms (a “C₂-C₂₀ alkenylene”), having 2 to 10 carbon atoms (a “C₂-C₁₀ alkenylene”), having 6 to 10 carbon atoms (a “C₆-C₁₀ alkenylene”), having 2 to 6 carbon atoms (a “C₂-C₆ alkenylene”), 2 to 4 carbon atoms (a “C₂-C₄ alkenylene”) or 2 to 3 carbon atoms (a “C₂-C₃ alkenylene”). Examples of alkenylene include, but are not limited to, groups such as ethenylene (or vinylene) (—CH═CH—), propenylene (—CH═CHCH₂—), 1,4-but-1-enylene (—CH═CH—CH₂CH₂—), 1,4-but-2-enylene (—CH₂CH═CHCH₂—), 1,6-hex-1-enylene (—CH═CH—(CH₂)₃CH₂—), and the like.

“Alkynyl” as used herein refers to and includes, unless otherwise stated, an unsaturated linear (i.e., unbranched) or branched univalent hydrocarbon chain or combination thereof, having at least one site of acetylenic unsaturation (i.e., having at least one moiety of the formula C≡C) and having the number of carbon atoms designated (i.e., C₂-C₁₀ means two to ten carbon atoms). Particular alkynyl groups are those having 2 to 20 carbon atoms (a “C₂-C₂₀ alkynyl”), having 6 to 10 carbon atoms (a “C₆-C₁₀ alkynyl”), having 2 to 8 carbon atoms (a “C₂-C₈ alkynyl”), having 2 to 6 carbon atoms (a “C₂-C₆ alkynyl”), or having 2 to 4 carbon atoms (a “C₂-C₄ alkynyl”). Examples of alkynyl group include, but are not limited to, groups such as ethynyl (or acetylenyl), prop-1-ynyl, prop-2-ynyl (or propargyl), but-1-ynyl, but-2-ynyl, but-3-ynyl, and the like.

“Alkynylene” as used herein refers to the same residues as alkynyl, but having bivalency. Particular alkynylene groups are those having 2 to 20 carbon atoms (a “C₂-C₂₀ alkynylene”), having 2 to 10 carbon atoms (a “C₂-C₁₀ alkynylene”), having 6 to 10 carbon atoms (a “C₆-C₁₀ alkynylene”), having 2 to 6 carbon atoms (a “C₂-C₆ alkynylene”), 2 to 4 carbon atoms (a “C₂-C₄ alkynylene”) or 2 to 3 carbon atoms (a “C₂-C₃ alkynylene”). Examples of alkynylene include, but are not limited to, groups such as ethynylene (or acetylenylene) (—C≡C—), propynylene (—C≡CCH₂—), and the like.

“Cycloalkyl” as used herein refers to and includes, unless otherwise stated, saturated cyclic univalent hydrocarbon structures, having the number of carbon atoms designated (i.e., C₃-C₁₀ means three to ten carbon atoms). Cycloalkyl can consist of one ring, such as cyclohexyl, or multiple rings, such as adamantyl. A cycloalkyl comprising more than one ring may be fused, spiro or bridged, or combinations thereof. Particular cycloalkyl groups are those having from 3 to 12 annular carbon atoms. A preferred cycloalkyl is a cyclic hydrocarbon having from 3 to 8 annular carbon atoms (a “C₃-C₈ cycloalkyl”), having 3 to 6 annular carbon atoms (a “C₃-C₆ cycloalkyl”), or having from 3 to 4 annular carbon atoms (a “C₃-C₄ cycloalkyl”). Examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, norbornyl, and the like.

“Cycloalkylene” as used herein refers to the same residues as cycloalkyl, but having bivalency. Cycloalkylene can consist of one ring or multiple rings which may be fused, spiro or bridged, or combinations thereof. Particular cycloalkylene groups are those having from 3 to 12 annular carbon atoms. A preferred cycloalkylene is a cyclic hydrocarbon having from 3 to 8 annular carbon atoms (a “C₃-C₈ cycloalkylene”), having 3 to 6 carbon atoms (a “C₃-C₆ cycloalkylene”), or having from 3 to 4 annular carbon atoms (a “C₃-C₄ cycloalkylene”). Examples of cycloalkylene include, but are not limited to, cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, norbornylene, and the like. A cycloalkylene may attach to the remaining structures via the same ring carbon atom (e.g., 1,1-cyclopropylene) or different ring carbon atoms (e.g., 1,2-cyclopropylene). When a cycloalkylene attaches to the remaining structures via two different ring carbon atoms, the connecting bonds may be cis or trans to each other (e.g., cis-1,2-cyclopropylene or trans-1,2-cyclopropylene). If points of attachment are not specified, the moiety can include any chemically possible attachments. For example, cyclopropylene can indicate 1,1-cyclopropylene or 1,2-cyclopropylene (e.g., cis-1,2-cyclopropylene, trans-1,2-cyclopropylene, or a mixture thereof), or a mixture thereof.

“Cycloalkenyl” refers to and includes, unless otherwise stated, an unsaturated cyclic non-aromatic univalent hydrocarbon structure, having at least one site of olefinic unsaturation (i.e., having at least one moiety of the formula C═C) and having the number of carbon atoms designated (i.e., C₃-C₁₀ means three to ten carbon atoms). Cycloalkenyl can consist of one ring, such as cyclohexenyl, or multiple rings, such as norbornenyl. A preferred cycloalkenyl is an unsaturated cyclic hydrocarbon having from 3 to 8 annular carbon atoms (a “C₃-C₈ cycloalkenyl”). Examples of cycloalkenyl groups include, but are not limited to, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, norbornenyl, and the like.

“Cycloalkenylene” as used herein refers to the same residues as cycloalkenyl, but having bivalency.

“Aryl” or “Ar” as used herein refers to an unsaturated aromatic carbocyclic group having a single ring (e.g., phenyl) or multiple condensed rings (e.g., naphthyl or anthryl) which condensed rings are carbocyclic and may or may not be aromatic, provided at least one ring in the multiple condensed ring structure is aromatic. Particular aryl groups are those having from 6 to 14 annular carbon atoms (a “C₆-C₁₄ aryl”). An aryl group having more than one ring where at least one ring is non-aromatic may be connected to the parent structure at either an aromatic ring position or at a non-aromatic ring position. In one variation, an aryl group having more than one ring where at least one ring is non-aromatic is connected to the parent structure at an aromatic ring position.

“Arylene” as used herein refers to the same residues as aryl, but having bivalency. Particular arylene groups are those having from 6 to 14 annular carbon atoms (a “C₆-C₁₄ arylene”).

“Heteroaryl” as used herein refers to an unsaturated aromatic cyclic group having from 1 to 14 annular carbon atoms and at least one annular heteroatom, including but not limited to heteroatoms such as nitrogen, oxygen and sulfur. A heteroaryl group may have a single ring (e.g., pyridyl, furyl) or multiple condensed rings (e.g., indolizinyl, benzothienyl) which condensed rings may be carbocyclic or may contain one or more annular heteroatom and which may or may not be aromatic, provided at least one ring in the multiple condensed ring structure is both aromatic and contains at least one annular heteroatom. Particular heteroaryl groups are 5 to 14-membered rings having 1 to 12 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, oxygen and sulfur, 5 to 10-membered rings having 1 to 8 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur, or 5, 6 or 7-membered rings having 1 to 5 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur. In one variation, particular heteroaryl groups are monocyclic aromatic 5-, 6- or 7-membered rings having from 1 to 6 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur. In another variation, particular heteroaryl groups are polycyclic aromatic rings having from 1 to 12 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, oxygen and sulfur. A heteroaryl group having more than one ring where at least one ring is non-aromatic may be connected to the parent structure at either an aromatic ring position or at a non-aromatic ring position. In one variation, a heteroaryl group having more than one ring where at least one ring is non-aromatic is connected to the parent structure at an aromatic ring position. A heteroaryl group may be connected to the parent structure at a ring carbon atom or a ring heteroatom.

“Heteroarylene” as used herein refers to the same residues as heteroaryl, but having bivalency.

“Heterocycle”, “heterocyclic”, or “heterocyclyl” as used herein refers to a saturated or an unsaturated non-aromatic cyclic group having from 1 to 14 annular carbon atoms and from 1 to 6 annular heteroatoms, such as nitrogen, sulfur or oxygen, and the like. A heterocyclic group may have a single ring (e.g., pyrrolidinyl) or multiple condensed rings (e.g., decahydroisoquinolin-1-yl), which condensed rings may or may not be aromatic and which may be carbocylic or contain one or more annular heteroatoms, but which excludes heteroaryl rings. A heterocycle comprising more than one ring may be fused, bridged or spiro, or any combination thereof. In fused ring systems, one or more of the fused rings can be cycloalkyl or aryl, but excludes heteroaryl groups. The heterocyclyl group may be optionally substituted independently with one or more substituents described herein. Particular heterocyclyl groups are 3 to 14-membered rings having 1 to 13 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, oxygen and sulfur, 3 to 12-membered rings having 1 to 11 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, oxygen and sulfur, 3 to 10-membered rings having 1 to 9 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur, 3 to 8-membered rings having 1 to 7 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur, or 3 to 6-membered rings having 1 to 5 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur. In one variation, heterocyclyl includes monocyclic 3-, 4-, 5-, 6- or 7-membered rings having from 1 to 2, 1 to 3, 1 to 4, 1 to 5, or 1 to 6 annular carbon atoms and 1 to 2, 1 to 3, or 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur. In another variation, heterocyclyl includes polycyclic non-aromatic rings having from 1 to 12 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, oxygen and sulfur.

“Heterocyclylene” as used herein refers to the same residues as heterocyclyl, but having bivalency.

“Halo” or “halogen” refers to elements of the Group 17 series having atomic number 9 to 85. Preferred halo groups include the radicals of fluorine, chlorine, bromine and iodine. Where a residue is substituted with one or more halogens, it may be referred to by using the prefix “halo,” e.g., haloaryl, haloalkyl, etc. refer to aryl and alkyl substituted with one or more halo groups, which in the case of two or more halo groups may be, but are not necessarily the same halogen. Where a residue is substituted with more than one halogen, it may be referred to by using a prefix corresponding to the number of halogen moieties attached, e.g., dihaloaryl, dihaloalkyl, trihaloaryl etc. refer to aryl and alkyl substituted with two (“di”) or three (“tri”) halo groups, which may be but are not necessarily the same halogen; thus 4-chloro-3-fluorophenyl is within the scope of dihaloaryl. An alkyl group in which each hydrogen is replaced with a halo group is referred to as a “perhaloalkyl.” A preferred haloalkyl, e.g., perhaloalkyl group is trifluoromethyl (—CF₃). Similarly, “perhaloalkoxy” refers to an alkoxy group in which a halogen takes the place of each H in the hydrocarbon making up the alkyl moiety of the alkoxy group. An example of a perhaloalkoxy group is trifluoromethoxy (—OCF₃).

“Carbonyl” refers to the group C═O.

“Thiocarbonyl” refers to the group C═S.

“Oxo” refers to the moiety ═O.

“D” refers to deuterium (²H).

“Boc” refers to tert-butyloxycarbonyl.

“Cbz” refers to carboxybenzyl.

“HATU” refers to 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate.

“BOP” refers to benzotriazol-1-yloxytris(dimethyamino)phosphonium hexafluorophosphate.

“PyBOP” refers to benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate.

“Optionally substituted” unless otherwise specified means that a group may be unsubstituted or substituted by one or more (e.g., 1, 2, 3, 4 or 5) of the substituents listed for that group in which the substituents may be the same of different. In one embodiment, an optionally substituted group has one substituent. In another embodiment, an optionally substituted group has two substituents. In another embodiment, an optionally substituted group has three substituents. In another embodiment, an optionally substituted group has four substituents. In some embodiments, an optionally substituted group has 1 to 2, 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, or 2 to 5 substituents. In one embodiment, an optionally substituted group is unsubstituted.

Unless clearly indicated otherwise, “an individual” as used herein intends a mammal, including but not limited to a primate, human, bovine, horse, feline, canine, or rodent. In one variation, the individual is a human.

As used herein, “treatment” or “treating” is an approach for obtaining beneficial or desired results including clinical results. For purposes of this invention, beneficial or desired results include, but are not limited to, one or more of the following: decreasing one more symptoms resulting from the disease, diminishing the extent of the disease, stabilizing the disease (e.g., preventing or delaying the worsening of the disease), preventing or delaying the spread of the disease, delaying the occurrence or recurrence of the disease, delay or slowing the progression of the disease, ameliorating the disease state, providing a remission (whether partial or total) of the disease, decreasing the dose of one or more other medications required to treat the disease, enhancing effect of another medication, delaying the progression of the disease, increasing the quality of life, and/or prolonging survival. Also encompassed by “treatment” is a reduction of pathological consequence of fibrosis. The methods of the invention contemplate any one or more of these aspects of treatment.

As used herein, the term “effective amount” intends such amount of a compound of the invention which should be effective in a given therapeutic form. As is understood in the art, an effective amount may be in one or more doses, i.e., a single dose or multiple doses may be required to achieve the desired treatment endpoint. An effective amount may be considered in the context of administering one or more therapeutic agents (e.g., a compound, or pharmaceutically acceptable salt thereof), and a single agent may be considered to be given in an effective amount if, in conjunction with one or more other agents, a desirable or beneficial result may be or is achieved. Suitable doses of any of the co-administered compounds may optionally be lowered due to the combined action (e.g., additive or synergistic effects) of the compounds.

A “therapeutically effective amount” refers to an amount of a compound or salt thereof sufficient to produce a desired therapeutic outcome.

As used herein, “unit dosage form” refers to physically discrete units, suitable as unit dosages, each unit containing a predetermined quantity of active ingredient calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. Unit dosage forms may contain a single or a combination therapy.

As used herein, the term “controlled release” refers to a drug-containing formulation or fraction thereof in which release of the drug is not immediate, i.e., with a “controlled release” formulation, administration does not result in immediate release of the drug into an absorption pool. The term encompasses depot formulations designed to gradually release the drug compound over an extended period of time. Controlled release formulations can include a wide variety of drug delivery systems, generally involving mixing the drug compound with carriers, polymers or other compounds having the desired release characteristics (e.g., pH-dependent or non-pH-dependent solubility, different degrees of water solubility, and the like) and formulating the mixture according to the desired route of delivery (e.g., coated capsules, implantable reservoirs, injectable solutions containing biodegradable capsules, and the like).

As used herein, by “pharmaceutically acceptable” or “pharmacologically acceptable” is meant a material that is not biologically or otherwise undesirable, e.g., the material may be incorporated into a pharmaceutical composition administered to a patient without causing any significant undesirable biological effects or interacting in a deleterious manner with any of the other components of the composition in which it is contained. Pharmaceutically acceptable carriers or excipients have preferably met the required standards of toxicological and manufacturing testing and/or are included on the Inactive Ingredient Guide prepared by the U.S. Food and Drug Administration.

“Pharmaceutically acceptable salts” are those salts which retain at least some of the biological activity of the free (non-salt) compound and which can be administered as drugs or pharmaceuticals to an individual. Such salts, for example, include: (1) acid addition salts, formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like; or formed with organic acids such as acetic acid, oxalic acid, propionic acid, succinic acid, maleic acid, tartaric acid and the like; (2) salts formed when an acidic proton present in the parent compound either is replaced by a metal ion, e.g., an alkali metal ion, an alkaline earth ion, or an aluminum ion; or coordinates with an organic base. Acceptable organic bases include ethanolamine, diethanolamine, triethanolamine and the like. Acceptable inorganic bases which can be used to prepared salts include aluminum hydroxide, calcium hydroxide, potassium hydroxide, sodium carbonate, sodium hydroxide, and the like. Pharmaceutically acceptable salts can be prepared in situ in the manufacturing process, or by separately reacting a purified compound of the invention in its free acid or base form with a suitable organic or inorganic base or acid, respectively, and isolating the salt thus formed during subsequent purification.

The term “excipient” as used herein means an inert or inactive substance that may be used in the production of a drug or pharmaceutical, such as a tablet containing a compound of the invention as an active ingredient. Various substances may be embraced by the term excipient, including without limitation any substance used as a binder, disintegrant, coating, compression/encapsulation aid, cream or lotion, lubricant, solutions for parenteral administration, materials for chewable tablets, sweetener or flavoring, suspending/gelling agent, or wet granulation agent. Binders include, e.g., carbomers, povidone, xanthan gum, etc.; coatings include, e.g., cellulose acetate phthalate, ethylcellulose, gellan gum, maltodextrin, enteric coatings, etc.; compression/encapsulation aids include, e.g., calcium carbonate, dextrose, fructose dc (dc=“directly compressible”), honey dc, lactose (anhydrate or monohydrate; optionally in combination with aspartame, cellulose, or microcrystalline cellulose), starch dc, sucrose, etc.; disintegrants include, e.g., croscarmellose sodium, gellan gum, sodium starch glycolate, etc.; creams or lotions include, e.g., maltodextrin, carrageenans, etc.; lubricants include, e.g., magnesium stearate, stearic acid, sodium stearyl fumarate, etc.; materials for chewable tablets include, e.g., dextrose, fructose dc, lactose (monohydrate, optionally in combination with aspartame or cellulose), etc.; suspending/gelling agents include, e.g., carrageenan, sodium starch glycolate, xanthan gum, etc.; sweeteners include, e.g., aspartame, dextrose, fructose dc, sorbitol, sucrose dc, etc.; and wet granulation agents include, e.g., calcium carbonate, maltodextrin, microcrystalline cellulose, etc.

Unless otherwise stated, “substantially pure” intends a composition that contains no more than 10% impurity, such as a composition comprising less than about 9%, 7%, 5%, 3%, 1%, 0.5% impurity.

It is understood that aspects and embodiments described herein as “comprising” include “consisting of” and “consisting essentially of” embodiments.

When a composition is described as “consisting essentially of” the listed components, the composition contains the components expressly listed, and may contain other components which do not substantially affect the disease or condition being treated such as trace impurities. However, the composition either does not contain any other components which do substantially affect the disease or condition being treated other than those components expressly listed; or, if the composition does contain extra components other than those listed which substantially affect the disease or condition being treated, the composition does not contain a sufficient concentration or amount of those extra components to substantially affect the disease or condition being treated. When a method is described as “consisting essentially of” the listed steps, the method contains the steps listed, and may contain other steps that do not substantially affect the disease or condition being treated, but the method does not contain any other steps which substantially affect the disease or condition being treated other than those steps expressly listed.

Compounds

In one aspect, provided is a compound of formula (I):

or a salt thereof, wherein:

R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl optionally substituted by R⁴, 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl optionally substituted by R⁴, 6-aminopyridin-2-yl optionally substituted by R⁴, or (pyridin-2-yl)amino optionally substituted by R⁴;

G is —C(O)R² or R³;

R² is C₁-C₆ alkyl optionally substituted by R^(2a), C₃-C₈ cycloalkyl optionally substituted by R^(2b), 3- to 12-membered heterocyclyl optionally substituted by R^(2c), C₆-C₁₄ aryl optionally substituted by R^(2d), 5- to 10-membered heteroaryl optionally substituted by R^(2e), —OR^(2f), or —NR^(2g)R^(2h);

R³ is C₁-C₆ alkyl optionally substituted by R^(3a), C₃-C₈ cycloalkyl optionally substituted by R^(3b), 3- to 12-membered heterocyclyl optionally substituted by R^(3c), C₆-C₁₄ aryl optionally substituted by R^(3d), or 5- to 10-membered heteroaryl optionally substituted by R^(3e);

L¹ is C₂-C₄ alkylene optionally substituted by R⁴;

L² is a bond or C₁-C₃ alkylene optionally substituted by R⁴;

L³ is C₂-C₄ alkylene optionally substituted by R⁴;

Y is a bond or C₃-C₈ cycloalkylene optionally substituted by Y^(a);

R^(2f) is C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, or 5- to 10-membered heteroaryl, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2f) are independently optionally substituted by R^(2i);

R^(2g) and R^(2h) are each independently hydrogen, deuterium, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, or 5- to 10-membered heteroaryl, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2g) and R^(2h) are independently optionally substituted by R^(2j);

each R^(2a), R^(2b), R^(2c), R^(2d), R^(2e), R^(2i), R^(2j), R^(3a), R^(3b), R^(3c), R^(3d), R^(3e) and Y^(a) is independently oxo or R⁴;

each R⁴ is independently deuterium, halogen, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, —CN, —OR⁵, —SR⁵, —NR⁶R⁷, —NO₂, —C═NH(ORS), —C(O)R⁵, —OC(O)R⁵, —C(O)OR⁵, —C(O)NR⁶R⁷, —NR⁵C(O)R⁶, —NR⁵C(O)OR⁶, —NR⁵C(O)NR⁶R⁷, —S(O)R⁵, —S(O)₂R⁵, —NR⁵S(O)R⁶, —NR⁵S(O)₂R⁶, —S(O)NR⁶R⁷, —S(O)₂NR⁶R⁷, or —P(O)(OR⁵)(OR⁶), wherein the C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R⁴ are independently optionally substituted by R^(4a);

each R^(4a) is independently deuterium, halogen, oxo, —OR, —NR⁸R⁹, —C(O)R⁸, —C(O)OR⁸, —NR⁸C(O)OR¹⁰, —CN, —S(O)R⁸, —S(O)₂R⁸, —P(O)(OR⁸)(OR⁹), C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, 5- to 10-membered heteroaryl, C₆-C₁₄ aryl, or C₁-C₆ alkyl, wherein the 3- to 12-membered heterocyclyl, 5- to 10-membered heteroaryl, C₆-C₁₄ aryl, and C₁-C₆ alkyl of R^(4a) are independently optionally substituted by R^(4b);

each R^(4b) is independently deuterium, oxo, —OH, —O(²H), halogen, or C₁-C₆ alkyl optionally substituted by deuterium, halogen, —OH, —O(²H), or oxo;

each R⁵ is independently hydrogen, deuterium, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, or 3- to 10-membered heterocyclyl, wherein the C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, and 3- to 10-membered heterocyclyl of R⁵ are each independently optionally substituted by R^(5a);

each R^(5a) is independently halogen, deuterium, oxo, —CN, —OR¹, —NR¹¹R¹², —P(O)(OR¹¹)(OR¹²), 3- to 12-membered heterocyclyl, or C₁-C₆ alkyl optionally substituted by deuterium, halogen, —OH, —O(²H), or oxo;

each R⁶ is independently hydrogen, deuterium, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, or 3- to 6-membered heterocyclyl, wherein the C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, and 3- to 6-membered heterocyclyl of R⁶ are independently optionally substituted by deuterium, halogen, oxo, —CN, —OR¹⁰, —NR¹¹R¹², or C₁-C₆ alkyl optionally substituted by deuterium, halogen, —OH, —O(²H), or oxo;

each R⁷ is independently hydrogen, deuterium, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, or 3- to 6-membered heterocyclyl, wherein the C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, and 3- to 6-membered heterocyclyl of R⁷ are independently optionally substituted by deuterium, halogen, oxo, —CN, —OR¹⁰, —NR¹¹R¹², or C₁-C₆ alkyl optionally substituted by deuterium, halogen, —OH, —O(²H), or oxo;

or R⁶ and R⁷ are taken together with the atom to which they are attached to form a 3- to 10-membered heterocyclyl optionally substituted by deuterium, halogen, oxo, —OR¹⁰, —NR¹¹R¹², or C₁-C₆ alkyl optionally substituted by deuterium, halogen, oxo, —OH, or —O(²H);

each R⁸ is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo;

each R⁹ is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo;

each R¹⁰ is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo;

each R¹¹ is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo; and

each R¹² is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo; or R¹¹ and R¹² are taken together with the atom to which they are attached to form a 3-6 membered heterocyclyl optionally substituted by deuterium, halogen, oxo or C₁-C₆ alkyl optionally substituted by deuterium, oxo, or halogen.

In one variation is provided a compound of the formula (I), or a salt thereof, wherein the carbon bearing the CO₂H and N(H)G moieties is in the “S” configuration. In another variation is provided a compound of the formula (I), or a salt thereof, wherein the carbon bearing the CO₂H and N(H)G moieties is in the “R” configuration. Mixtures of a compound of the formula (I) are also embraced, including racemic or non-racemic mixtures of a given compound, and mixtures of two or more compounds of different chemical formulae.

In the descriptions herein, it is understood that every description, variation, embodiment or aspect of a moiety may be combined with every description, variation, embodiment or aspect of other moieties the same as if each and every combination of descriptions is specifically and individually listed. For example, every description, variation, embodiment or aspect provided herein with respect to G of formula (I) may be combined with every description, variation, embodiment or aspect of L¹, L², Y, L² and/or R¹ the same as if each and every combination were specifically and individually listed. It is also understood that all descriptions, variations, embodiments or aspects of formula (I), where applicable, apply equally to other formulae detailed herein, and are equally described, the same as if each and every description, variation, embodiment or aspect were separately and individually listed for all formulae. For example, all descriptions, variations, embodiments or aspects of formula (I), where applicable, apply equally to any of formulae (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), and (Vb-2) detailed herein, and are equally described, the same as if each and every description, variation, embodiment or aspect were separately and individually listed for all formulae.

In some embodiments of the compound of formula (I), or a salt thereof, L¹ is unsubstituted C₂-C₄ alkylene. In a particular variation, L¹ is —CH₂—CH₂—, —CH₂—CH₂—CH₂—, or —CH₂—CH₂—CH₂—CH₂—. In another variation, L¹ is —CH₂—CH₂—.

In some embodiments of the compound of formula (I), or a salt thereof, -L²- is a bond.

In some embodiments of the compound of formula (I), or a salt thereof, —Y— is a bond.

In some embodiments of the compound of formula (I), or a salt thereof, —Y— is a C₃-C₄ cycloalkylene. In one aspect, Y is a C₃ cycloalkylene. In another aspect, Y is a C₄ cycloalkylene. In one variation, the point of attachment of the C₃-C₄ cycloalkylene to L² and L³ are via the same carbon atom

In another variation, the point of attachment of the C₃-C₄ cycloalkylene to L² and L³ are via two different carbon atoms

In another variation, when the point of attachment of the C₃-C₄ cycloalkylene to L² and L³ are via two different carbon atoms, the stereochemistry introduced at the C₃-C₄ cycloalkylene is trans

In another variation, when the point of attachment of the C₃-C₄ cycloalkylene to L² and L³ are via two different carbon atoms, the stereochemistry introduced at the C₃-C₄ cycloalkylene is cis

In some embodiments of the compound of formula (I), or a salt thereof, at least one of R^(2g), R^(2h), R⁴, R^(4a), R^(4b), R⁵, R^(5a), R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, or R¹² is deuterium.

In some embodiments of the compound of formula (I), or a salt thereof, -L²-Y-L³- are taken together to form a moiety selected from the group consisting of: —CH₂CH₂CH₂—, —CH₂(CH₂)₂CH₂—, —CH₂(CH₂)₃CH₂—,

wherein the wavy lines denote attachment points to the parent molecule.

In some embodiments of the compound of formula (I), or a salt thereof, -L¹-O-L²-Y-L³- are taken together to form a moiety selected from the group consisting of:

wherein

is a C₃-C₈ cycloalkylene optionally substituted by Y^(a), and

wherein

is a C₃-C₈ cycloalkylene optionally substituted by Y^(a).

In some embodiments of the compound of formula (I), or a salt thereof, -L¹-O-L²-Y-L³- are taken together to form a moiety selected from the group consisting of:

In another variation, -L¹-O-L²-Y-L³- are taken together to form a moiety selected from the group consisting of:

In another particular variation, -L¹-O-L²-Y-L³- are taken together to form a moiety selected from the group consisting of:

In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is 1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is cis-1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is trans-1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is 1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is cis-1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is trans-1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. For each individual preceding embodiment described in this paragraph, a further embodiment is disclosed in which among the substitutable ring atoms in R², one of: one saturated ring atom is substituted with C₁-C₆ haloalkyl, e.g., —CF₃; two aryl ring atoms are independently substituted with halogen; and 2 or 3 heteroaryl ring atoms are independently substituted with halogen or C₁-C₆ alkyl, e.g., methyl. Further, in various embodiments, each preceding embodiment described in this paragraph may be excluded from the compound represented by formula (I) and salts thereof.

In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is 1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is cis-1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is trans-1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —C(O)R², wherein R² is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂CH₂CH₂—, Y is a bond, and L³ is —CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is 1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is cis-1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. In an embodiment, the compound of formula (I) or a salt thereof is provided wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl; L¹ is —CH₂CH₂—, Y is trans-1,3-cyclobutyl, and L³ is —CH₂CH₂—; and G is —R³, wherein R³ is a six-membered heterocyclyl, aryl, or heteroaryl ring, wherein among the substitutable ring atoms in R², 1 saturated ring atom, or 2 or 3 unsaturated ring atoms are independently substituted with halogen, C₁-C₆ alkyl, or C₁-C₆ haloalkyl. For each individual preceding embodiment described in this paragraph, a further embodiment is disclosed in which among the substitutable ring atoms in R², one of: one saturated ring atom is substituted with C₁-C₆ haloalkyl, e.g., —CF₃; two aryl ring atoms are independently substituted with halogen; and 2 or 3 heteroaryl ring atoms are independently substituted with halogen or C₁-C₆ alkyl, e.g., methyl. Further, in various embodiments, each preceding embodiment described in this paragraph may be excluded from the compound represented by formula (I) and salts thereof.

In some embodiments, the compound of formula (I) is of the formula (IIa):

or a salt thereof, wherein R² is as defined for formula (I).

In some embodiments, the compound of formula (I) is of the formula (IIb):

or a salt thereof, wherein R³ is as defined for formula (I).

In some embodiments, the compound of formula (I) is of the formula (IIIa):

or a salt thereof, wherein R² is as defined for formula (I).

In some embodiments, the compound of formula (I) is of the formula (IIIb):

or a salt thereof, wherein R³ is as defined for formula (I).

In some embodiments, the compound of formula (I) is of the formula (IVa):

or a salt thereof, wherein R² is as defined for formula (I).

In some embodiments, the compound of formula (I) is of the formula (IVb):

or a salt thereof, wherein R³ is as defined for formula (I).

In some embodiments, the compound of formula (I) is of the formula (Va):

or a salt thereof, wherein R² is as defined for formula (I).

In some embodiments, the compound of formula (Va) is of the formula (Va-1):

or a salt thereof, wherein R² is as defined for formula (I).

In some embodiments, the compound of formula (Va) is of the formula (Va-2):

or a salt thereof, wherein R² is as defined for formula (I).

In some embodiments, the compound of formula (I) is of the formula (Vb):

or a salt thereof, wherein R³ is as defined for formula (I).

In some embodiments, the compound of formula (Vb) is of the formula (Vb-1):

or a salt thereof, wherein R³ is as defined for formula (I).

In some embodiments, the compound of formula (Vb) is of the formula (Vb-2):

or a salt thereof, wherein R³ is as defined for formula (I).

In some embodiments, the compound of formula (I) is of the formula:

wherein j and k are respectively 2 and 4, 3 and 3, or 4 and 2, or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

wherein j and k are respectively 2 and 4, 3 and 3, or 4 and 2, or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

In some embodiments, the compound of formula (I) is of the formula:

or a salt thereof.

Reference to formula (I) or any variation thereof includes reference to (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound of Table 1 or Table 2, or any one of compounds 1-329.

In some embodiments of the compound of formula (I), or a salt thereof, the compound is selected from the group consisting of

or a pharmaceutically acceptable salt thereof, wherein G is as defined for formula (I), or any applicable variation thereof, and the alpha-carbon of the amino acid can have either R or S absolute stereochemistry as indicated. In one such embodiment, the alpha-carbon of the amino acid is in the S absolute stereochemistry. When the alpha-carbon of the amino acid is in the S absolute stereochemical configuration, in some embodiments such a compound is substantially isolated from the corresponding compound in which the amino acid is in the R absolute stereochemical configuration, such as when a composition comprising the compound in the S absolute stereochemical configuration comprises no more than 5% or 3% or 1% or 0.5% or 0.1% by weight of the corresponding compound having the R absolute stereochemical configuration. In another such embodiment, the alpha-carbon of the amino acid is in the R absolute stereochemistry. When the alpha-carbon of the amino acid is in the R absolute stereochemical configuration, in some embodiments such a compound is substantially isolated from the corresponding compound in which the amino acid is in the S absolute stereochemical configuration, such as when a composition comprising the compound in the R absolute stereochemical configuration comprises no more than 5% or 3% or 1% or 0.5% or 0.1% by weight of the corresponding compound having the S absolute stereochemical configuration. In another embodiment is provided a composition comprising a foregoing compound, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier. In one such embodiment is provided a composition comprising a mixture of a compound in which the alpha-carbon of the amino acid is in the S stereochemical configuration and a compound in which the alpha-carbon of the amino acid is in the R stereochemical configuration.

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is C₁-C₆ alkyl substituted by 0-5 R^(2a) groups. In one aspect of the foregoing embodiment, R² is unsubstituted C₁-C₆ alkyl (e.g., unsubstituted C₄-C₆ alkyl). In one aspect of the foregoing embodiment, the C₁-C₆ alkyl of R² is straight-chain alkyl (e.g., n-butyl). In another aspect of the foregoing embodiment, the C₁-C₆ alkyl of R² is branched alkyl (e.g., iso-butyl). In another aspect of the foregoing embodiment, R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein each R^(2a) is independently selected from halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, —CN, —OR⁵, —NR⁶R⁷, —NR⁵C(O)OR⁶, and —S(O)₂R⁵, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2a) are independently optionally substituted by R^(4a). In another aspect of the foregoing embodiment, R² is C₂-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is halogen (e.g., R²C₅ alkyl substituted by 2-3 fluoro groups). In another aspect of the foregoing embodiment, R² is C₁-C₅ alkyl (e.g., C₁-C₃ alkyl) substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is C₃-C₈ cycloalkyl (e.g., cyclopropyl, cyclobutyl, and cyclohexyl). In another aspect of the foregoing embodiment, R² is C₁-C₃ alkyl substituted by C₃-C₆ cycloalkyl, wherein the C₃-C₆ cycloalkyl is substituted by 0-5 groups selected from the group consisting of halogen, C₁-C₆ alkyl (e.g., methyl), and —OR⁵ (e.g., —OH and —OCH₃). In another aspect of the foregoing embodiment, R² is C₁-C₃ alkyl substituted by C₃-C₆ cycloalkyl, wherein the C₃-C₆ cycloalkyl unsubstituted. In another aspect of the foregoing embodiment, R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is 3- to 12-membered heterocyclyl (e.g. R² is C₁ alkyl substituted by 6-membered heterocyclyl). In another aspect of the foregoing embodiment, R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is C₆-C₁₄ aryl, wherein the C₆-C₁₄ aryl is independently optionally substituted by halogen or C₁-C₆ alkyl substituted by 0-5 halogen (e.g., R^(2a) is unsubstituted phenyl or phenyl substituted by 1-5 halogen. In another aspect of the foregoing embodiment, R² is C₂-C₅ alkyl (e.g., C₅ alkyl) substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is 5- to 10-membered heteroaryl substituted by 0-5 R^(4a) groups (e.g., R^(2a) is unsubstituted pyridinyl). In another aspect of the foregoing embodiment, R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is —OR⁵, wherein each R⁵ is independently selected from hydrogen, C₁-C₆ alkyl, and C₆-C₁₄ aryl (e.g., R⁵ is C₆-C₁₄ aryl substituted by 0-5 halogen). In another aspect of the foregoing embodiment, R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is —CN, —NR⁶R⁷, —NR⁵C(O)OR⁶, or —S(O)₂R⁵. In another aspect of the foregoing embodiment, R² is C₁-C₅ alkyl substituted by 2-5 R^(2a) groups, wherein each R^(2a) is independently selected from halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 5- to 10-membered heteroaryl, C₆-C₁₄ aryl, —CN, —OR⁵, and —NR⁵C(O)OR⁶. In another aspect of the foregoing embodiment, R² is C₁-C₅ alkyl substituted by 2-5 R^(2a) groups, wherein at least one R^(2a) group is phenyl substituted by 0-5 halogen and at least one R^(2a) group is OR⁵, wherein each R⁵ is independently selected from hydrogen and C₁-C₆ alkyl.

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein each R^(2a) is independently as defined for formula (I).

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is C₃-C₈ cycloalkyl substituted by 0-5 R^(2b) groups. In another aspect of the foregoing embodiment, the C₃-C₈ cycloalkyl of R² is monocyclic. In another aspect, the C₃-C₈ cycloalkyl of R² is bicyclic (e.g., fused, spiro, or bridged). In another aspect, R² is unsubstituted C₃-C₈ cycloalkyl (e.g., bicycle[2.2.2]octanyl). In another aspect of the foregoing embodiment, R² is C₃-C₈ cycloalkyl substituted by 1-5 R^(2b) groups, wherein each R^(2b) is independently selected from halogen, C₁-C₆ alkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, and —OR⁵. In another aspect of the foregoing embodiment, R² is C₃-C₆ cycloalkyl (e.g., cyclopropyl or cyclohexyl) substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is halogen (e.g., fluoro). In another aspect of the foregoing embodiment, R² is C₃-C₆ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is C₁-C₆ alkyl, wherein the C₁-C₆ alkyl of R^(2b) is substituted by 0-5 R^(4a) groups (e.g., R^(2b) is C₁-C₂ alkyl substituted by 1-5 R^(4a) groups, wherein each R^(4a) groups is independently selected from phenyl substituted by 0-5 halogen and 6-membered heteroaryl substituted by 0-5 halogen). In another aspect of the foregoing embodiment, R² is C₃-C₆ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is 3- to 12-membered heterocyclyl (e.g., tetrahydro-2H-pyranyl or benzodioxolyl). In another aspect of the foregoing embodiment, R² is C₃-C₄ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is C₆-C₁₄ aryl substituted by 0-5 R^(4a) groups, wherein each R^(4a) is independently selected from halogen, C₁-C₆ alkyl, and —OR⁸ (e.g., R^(2b) is unsubstituted phenyl or R^(2b) is phenyl substituted by fluoro, methyl, tert-butyl, or —OCF₃). In another aspect of the foregoing embodiment, R² is C₃-C₇ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is 5- to 10-membered heteroaryl (e.g., pyridinyl or isoquinolinyl). In another aspect of the foregoing embodiment, R² is C₃-C₆ cycloalkyl substituted by 2-5 R^(2b) groups, wherein each R^(2b) is independently selected from halogen (e.g., fluoro), C₆-C₁₄ aryl (e.g., phenyl), and —OR⁵ (e.g., —OH). In another aspect of the foregoing embodiment, R² is C₃-C₆ cycloalkyl substituted by 2-5 R^(2b) groups, wherein at least one R^(2b) group is halogen (e.g., fluoro) and at least one R^(2b) group is phenyl substituted by 0-5 C₁-C₆ alkyl (e.g., —CH₃).

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein R^(2b) is as defined for formula (I), and n is 0, 1, 2, or 3. In one variation, n is 0. In another variation, n is 1. In another variation, n is 2. In yet another variation, n is 3.

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is 3- to 12-membered heterocyclyl substituted by 0-5 R^(2c) groups. In another aspect of the foregoing embodiment, the 3- to 12-membered heterocyclyl of R² is monocyclic. In another aspect of the foregoing embodiment, the 3- to 12-membered heterocyclyl of R² is bicyclic (e.g., fused, spiro, or bridged). In another aspect of the foregoing embodiment, R² unsubstituted 4- to 10-membered heterocyclyl (e.g., azetidinyl, pyrrolidinyl, piperidinyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, oxabicyclohexanyl, oxabicyclooctanyl, tetrahydro-2H-thiopyranyl, morpholinyl, benzodioxanyl, 3-oxabicyclo[3.1.0]hexanyl, or 8-oxabicyclo[3.2.1]octanyl). In another aspect of the foregoing embodiment, R² is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein each R^(2c) is independently selected from oxo, halogen, C₁-C₆ alkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, —CN, —OR⁵, —C(O)R⁵, —C(O)OR⁵, and —S(O)₂R⁵. In another aspect of the foregoing embodiment, R² is 4- to 6-membered heterocyclyl (e.g., oxetanyl, tetrahydropyranyl, or azetidinyl) substituted by 1-5 R²C groups, wherein at least one of the R²C groups is C₁-C₆ alkyl, wherein the C₁-C₆ alkyl of R²C is substituted by 0-5 R^(4a) groups. In another aspect of the foregoing embodiment, R²C is C₁-C₂ alkyl substituted by 1-5 R^(4a) groups, wherein each R^(4a) groups is independently selected from halogen; phenyl substituted by 0-5 halogen; 6-membered heteroaryl (e.g., pyridinyl or pyrimidinyl) substituted by 0-5 halogen; and —NR⁸C(O)OR¹⁰ (e.g. —NHC(O)O-t-butyl). In another aspect of the foregoing embodiment, R² is 4- to 6-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein at least one of the R²C groups is unsubstituted C₆-C₁₄ aryl (e.g., phenyl). In another aspect of the foregoing embodiment, R² is 4- to 6-membered heterocyclyl (e.g., 5-membered heterocyclyl) substituted by 1-5 R²C groups, wherein at least one of the R²C groups is 5- to 10-membered heteroaryl substituted by 0-5 C₁-C₆ alkyl (e.g., R²C is pyrazolyl substituted by —CH₃). In another aspect of the foregoing embodiment, R² is 4- to 6-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein at least one R²C group is —C(O)R⁵, —C(O)OR⁵, or —S(O)₂R⁵, wherein each R⁵ is independently C₁-C₆ alkyl. In another aspect of the foregoing embodiment, R² is 4- to 6-membered heterocyclyl (e.g., 1,2-dihydropyridinyl) substituted by 1-5 R²C groups, wherein at least one R²C group is oxo. In another aspect of the foregoing embodiment, R² is 4- to 6-membered heterocyclyl substituted by 2-5 R²C groups, wherein each R^(2c) is independently selected from halogen, C₁-C₆ alkyl, —C(O)R⁵, and —C(O)OR⁵. In another aspect of the foregoing embodiment, R² is 4- to 6-membered heterocyclyl substituted by 2-5 R²C groups, wherein at least one R²C group is C₁-C₆ alkyl substituted by 0-5 halogen and at least one R²C group is —C(O)R⁵ or —C(O)OR⁵. In another aspect of the foregoing embodiment, R² is azetidinyl, pyrrolidinyl, piperidinyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, oxabicyclohexanyl, oxabicyclooctanyl, tetrahydro-2H-thiopyranyl, morpholinyl, or benzodioxanyl, each of which is substituted by 0-5 R^(2c) groups.

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein R^(2c) is as defined for formula (I), and n is 0, 1, 2, or 3. In one variation, n is 0. In another variation, n is 1. In another variation, n is 2. In yet another variation, n is 3. In the above structures that depict an —N(H)— moiety and n is 1, 2, or 3, it is understood that one of the R^(2c) groups can replace the hydrogen atom of the —N(H)— moiety (e.g., n is 1 and R² is

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is C₆-C₁₄ aryl substituted by 0-5 R^(2d) groups. In another aspect of the foregoing embodiment, R² is unsubstituted C₆-C₁₀ aryl (e.g., phenyl, indanyl, or 1,2,3,4-tetrahydronaphthalenyl). In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl substituted by 1-5 R^(2d) groups, wherein each R^(2d) is independently selected from halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, 5- to 10-membered heteroaryl, —CN, and —OR⁵, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl and 5- to 10-membered heteroaryl of R^(2d) are each independently substituted by 0-5 halogen, C₁-C₆ alkyl or OR⁸. In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl substituted by 1-5 R^(2d) groups, wherein at least one of the R^(2d) groups is halogen (e.g., fluoro or chloro). In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl substituted by 1-5 R^(2d) groups, wherein at least one of the R^(2d) groups is C₁-C₆ alkyl, wherein the C₁-C₆ alkyl of R^(2d) is substituted by 0-5 R^(4a) groups (e.g., R^(2d) is —CH₃). In another aspect of the foregoing embodiment, R^(2d) is C₁-C₂ alkyl substituted by 1-5 R^(4a) groups, wherein each R^(4a) groups is independently selected from halogen and OR⁸ (e.g., R^(2d) is —CH₂(OH), or —CF₃). In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl (e.g, phenyl) substituted by 1-5 R^(2d) groups, wherein at least one of the R^(2d) groups is C₃-C₆ cycloalkyl (e.g., cyclopropyl). In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl (e.g, phenyl) substituted by 1-5 R^(2d) groups, wherein at least one of the R^(2d) groups is 6-membered heterocyclyl (e.g., morpholinyl). In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl (e.g, phenyl) substituted by 1-5 R^(2d) groups, wherein at least one of the R^(2d) groups is 5- to 6-membered heteroaryl (e.g., pyrazolyl, thiazolyl, or pyridinyl), wherein the heteroaryl of R^(2d) is substituted by 0-5 C₁-C₆ alkyl groups (e.g., —CH₃). In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl (e.g, phenyl) substituted by 1-5 R^(2d) groups, wherein at least one of the R^(2d) groups is —OR⁵, wherein each R⁵ is independently selected from C₁-C₂ alkyl substituted by 0-5 groups selected from halogen (e.g., fluoro) and —OR¹⁰ (e.g., —OCH₃). In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl (e.g, phenyl) substituted by 2-5 R^(2d) groups, wherein each R^(2d) is independently selected from halogen, C₁-C₆ alkyl, —CN, and —OR⁵. In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl (e.g, phenyl) substituted by 2-5 R^(2d) groups, wherein at least two of the R^(2d) groups are halogen (e.g., fluoro or chloro). In another aspect of the foregoing embodiment, R² is C₆-C₁₀ aryl (e.g, phenyl) substituted by 2-5 R^(2d) groups, wherein at least one of the R^(2d) groups is C₁-C₆ alkyl and at least one of the R^(2d) groups is selected from the group consisting of halogen, —CN, and —OR⁵. In another aspect of the foregoing embodiment, R² is phenyl, indanyl, or 1,2,3,4-tetrahydronaphthalenyl, each of which is substituted by 0-5 R^(2d) groups.

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein R^(2d) is as defined for formula (I), and n is 0, 1, 2, or 3. In one variation, n is 0. In another variation, n is 1. In another variation, n is 2. In yet another variation, n is 3.

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is 5- to 10-membered heteroaryl substituted by 0-5 R^(2e) groups. In another aspect of the foregoing embodiment, R² is unsubstituted 5- to 10-membered heteroaryl (e.g., pyridinyl, pyrrolopyridinyl, quinolinyl, or 4,5,6,7-tetrahydro-indazolyl). In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl substituted by 1-5 R^(2e) groups, wherein each R^(2e) is independently selected from halogen, C₁-C₆ alkyl, and —OR⁵. In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl (e.g., pyridinyl) substituted by 1-5 R^(2e) groups, wherein at least one of the R^(2e) groups is halogen. In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl (e.g., pyridinyl, pyrimidinyl, pyrrolopyridinyl, or indazolyl) substituted by 1-5 R^(2e) groups, wherein at least one of the R^(2e) groups is C₁-C₄ alkyl, wherein the C₁-C₄ alkyl of R²e is substituted by 0-5 halogen groups (e.g., R^(2e) is —CH₃ or —CF₃). In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl substituted by 2-5 R²e groups, wherein each R²e is independently selected from halogen, C₁-C₆ alkyl, and —CN. In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl substituted by 2-5 R^(2e) groups, wherein at least two of the R^(2e) groups are halogen. In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl substituted by 2-5 R^(2e) groups, wherein at least two of the R^(2e) groups are C₁-C₆ alkyl. In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl (e.g., pyridinyl or pyrimidinyl) substituted by 3-5 R^(2e) groups, wherein each R^(2e) is independently selected from halogen, C₁-C₆ alkyl, and —CN. In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl (e.g., pyridinyl or pyrimidinyl) substituted by three —CH₃ groups. In another aspect of the foregoing embodiment, R² is 5- to 10-membered heteroaryl (e.g., pyridinyl or pyrimidinyl) substituted by two —CH₃ groups and one halogen group. In another aspect of the foregoing embodiment, R² is pyrazolyl, pyridyl, pyrimidinyl, indazolyl, pyrrolopyridinyl, quinolinyl, or 4,5,6,7-tetrahydro-indazolyl, each of which is substituted by 0-5 R^(2e) groups.

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein R^(2e) is as defined for formula (I), and n is 0, 1, 2, or 3. In one variation, n is 0. In another variation, n is 1. In another variation, n is 2. In yet another variation, n is 3.

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is —OR^(2f). In another aspect of the foregoing embodiment, R²f is selected from the group consisting of C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl.

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R², R² is —OR^(2f), and R^(2f) is C₁-C₆ alkyl substituted by 0-5 R^(2i) groups. In another aspect of the foregoing embodiment, R^(2f) is unsubstituted C₁-C₆ alkyl. In another aspect of the foregoing embodiment, R^(2f) is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein each R²i is independently selected from the group consisting of halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, —OR⁵, —NR⁵C(O)R⁶, and —NR⁵C(O)OR⁶, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2i) is substituted by 0-5 groups selected from the group consisting of halogen, —CN, —OR⁸, and C₁-C₆ alkyl optionally substituted by halogen. In another aspect of the foregoing embodiment, R^(2f) is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein at least one of the R^(2i) groups is halogen. In another aspect of the foregoing embodiment, R²f is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein at least one of the R^(2i) groups is phenyl. In another aspect of the foregoing embodiment, R^(2f) is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein at least one of the R^(2i) groups is —NR⁵C(O)OR⁶, wherein R⁵ is hydrogen and R⁶ is C₁-C₆ alkyl (e.g., R^(2i) is —NHC(O)O-t-butyl). In another aspect of the foregoing embodiment, R^(2f) is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein at least one of the R^(2i) groups is —NR⁵C(O)R⁶, wherein R⁵ is hydrogen and R⁶ is C₁-C₆ alkyl (e.g., R^(2i) is —NHC(O)CH₃).

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein R^(2i) is as defined for formula (I).

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R², R² is —OR^(2f), and R^(2f) is C₃-C₈ cycloalkyl substituted by 0-5 R^(2i) groups. In another aspect of the foregoing embodiment, R^(2f) is unsubstituted C₃-C₈ cycloalkyl (e.g., cyclopentyl, cylcohexyl, or spiro[2.3]hexanyl). In another aspect of the foregoing embodiment, R^(2f) is C₃-C₈ cycloalkyl substituted by 1-5 R^(2i) groups, wherein each R^(2i) is independently selected from the group consisting of halogen, C₁-C₆ alkyl, C₂-C₆ alkynyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl, wherein the C₁-C₆ alkyl, C₂-C₆ alkynyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2i) are substituted by 0-5 groups selected from the group consisting of C₁-C₆ alkyl and C₆-C₁₄ aryl. In another aspect of the foregoing embodiment, R^(2f) is C₃-C₆ cycloalkyl (e.g., cyclopropyl or cyclobutyl) substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is C₁ alkyl. In another aspect of the foregoing embodiment, R^(2f) is C₃-C₆ cycloalkyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is C₂ alkynyl substituted by 0-1 phenyl group. In another aspect of the foregoing embodiment, R^(2f) is C₃-C₆ cycloalkyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is phenyl substituted by 0-3 C₁-C₆ alkyl groups or is pyrazolyl substituted by 0-3 C₁-C₆ alkyl groups, which C₁-C₆ alkyl groups on phenyl or pyrazolyl of R^(2i) may be the same or different.

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein R^(2i) is as defined for formula (I) and n is 0, 1, or 2. In one variation, n is 0. In another variation, n is 1. In yet another variation, n is 2.

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R², R² is —OR^(2f), and R^(2f) is 3- to 12-membered heterocyclyl substituted by 0-5 R^(2i) groups. In another aspect of the foregoing embodiment, R^(2f) is unsubstituted 3- to 12-membered heterocyclyl (e.g., azetidinyl or pyrrolidinyl). In another aspect of the foregoing embodiment, R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein each R^(2i) is independently selected from the group consisting of C₁-C₆ alkyl, C₂-C₆ alkynyl, C₆-C₁₄ aryl, —C(O)R⁵, —C(O)OR⁵, and —S(O)₂R⁵. In another aspect of the foregoing embodiment, R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is C₁-C₆ alkyl or C₂-C₆ alkynyl, each of which is unsubstituted or substituted by a phenyl group. In another aspect of the foregoing embodiment, R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is C₆-C₁₄ aryl (e.g., phenyl) substituted by 0-5 R^(4a) groups, wherein each R^(4a) is independently selected from the group consisting of halogen and C₁-C₆ alkyl (e.g., isopropyl). In another aspect of the foregoing embodiment, R^(2f) is 3- to 12-membered heterocyclyl (e.g., azetidinyl or pyrrolidinyl) substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is —C(O)R⁵, wherein R⁵ is C₁-C₆ alkyl (e.g, R^(2i) is —C(O)CH₃). In another aspect of the foregoing embodiment, R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is —C(O)OR⁵, wherein R⁵ is C₁-C₆ alkyl (e.g., R^(2i) is —C(O)O-t-butyl). In another aspect of the foregoing embodiment, R^(2f) is 3- to 12-membered heterocyclyl (e.g., azetidinyl or pyrrolidinyl) substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is —S(O)₂R⁵, wherein R⁵ is C₁-C₆ alkyl (e.g., R^(2i) is —S(O)₂CH₃). In another aspect of the foregoing embodiment, R^(2f) is 3- to 12-membered heterocyclyl substituted by 2-5 R^(2i) groups, wherein at least one R^(2i) group is —C(O)R⁵, —C(O)OR⁵, or —S(O)₂R⁵, wherein R⁵ is C₁-C₆ alkyl (e.g., R⁵ is —CH₃ or t-butyl). In another aspect of the foregoing embodiment, R^(2f) is azetidinyl, pyrrolidinyl, or tetrahydropyranyl, each of which is optionally substituted by 0-5 R^(2i).

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein R^(2i) is as defined for formula (I) and n is 0, 1, or 2. In one variation, n is 0. In another variation, n is 1. In yet another variation, n is 2. In the above structures that depict an —N(H)— moiety and n is 1 or 2, it is understood that one of the R^(2i) groups can replace the hydrogen atom of the —N(H)— moiety (e.g., n is 1 and R² is

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R², R² is —OR^(2f), and R^(2f) is C₆-C₁₄ aryl substituted by 0-5 R^(2i) groups. In another aspect of the foregoing embodiment, R^(2f) is unsubstituted C₆-C₁₄ aryl (e.g., indanyl or 1,2,3,4-tetrahydronaphthalenyl).

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

wherein R^(2i) is as defined for formula (I) and n is 0, 1, or 2. In one variation, n is 0. In another variation, n is 1. In yet another variation, n is 2.

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R², R² is —OR^(2f), and R^(2f) is 5- to 10-membered heteroaryl substituted by 0-5 R^(2i) groups. In another aspect of the foregoing embodiment, R^(2f) is unsubstituted 5- to 10-membered heteroaryl.

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is —NR^(2g)R^(2h). In another aspect of the foregoing embodiment, R^(2g) is hydrogen and R^(2h) is C₁-C₆ alkyl substituted by 0-5 halogen. In another aspect of the foregoing embodiment, R^(2g) is C₁-C₆ alkyl substituted by 0-5 halogen and R^(2h) is C₁-C₆ alkyl substituted by 0-5 halogen.

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:

Also provided in another embodiment is a compound of formula (I), or a salt thereof, wherein G is R³. In one aspect, R³ is 5- to 10-membered heteroaryl (e.g., pyrimidinyl or quinazolinyl) substituted by 0-5 R^(3e) groups, wherein each R^(3e) group is independently selected from halogen; C₁-C₆ alkyl optionally substituted by halogen; 5- to 10-membered heteroaryl optionally substituted by halogen or C₁-C₆ alkyl; and C₁-C₆ alkoxy. In one aspect, R³ is unsubstituted 5- to 10-membered heteroaryl. In one aspect, R³ is 5- to 10-membered heteroaryl substituted by 1-5 R^(3e) groups, wherein each R^(3e) group is independently selected from halogen, C₁-C₆ alkyl, and C₆-C₁₄ aryl. In one aspect, R³ is 5- to 10-membered heteroaryl substituted by 1-5 R^(3e) groups, wherein at least one R^(3e) group is halogen. In one aspect, R³ is 5- to 10-membered heteroaryl substituted by 1-5 R^(3e) groups, wherein at least one R^(3e) group is C₁-C₄ alkyl. In one aspect, R³ is 5- to 10-membered heteroaryl substituted by 1-5 R^(3e) groups, wherein at least one R^(3e) group is phenyl. In one aspect, R³ is 5- to 10-membered heteroaryl substituted by 2-5 R^(3e) groups, wherein at least one R^(3e) group is C₁-C₆ alkyl, and wherein at least one R^(3e) group is C₆-C₁₄ aryl.

Also provided is a compound of formula (I), or a salt thereof, wherein G is R³ and R³ is selected from the group consisting of:

wherein each R³e is independently R⁴. In the above structures wherein the —N(H)— moiety is present as shown and the structure it substituted by at least one R^(3e) group, it is understood that one of the R^(3e) groups can replace the hydrogen atom of the —N(H)— moiety (e.g., R³ is

Also provided is a compound of formula (I), or a salt thereof, wherein G is R³ and R³ is selected from the group consisting of:

Also provided is a compound of formula (I), or a salt thereof, wherein G is R³ and R³ is selected from the group consisting of:

Also provided is a compound of formula (I), or a salt thereof, wherein G is R³ and R³ is selected from the group consisting of:

Also provided is a compound of formula (I), or a salt thereof, wherein G is selected from the group consisting of:

In one aspect, provided is a compound of formula (I) or a salt thereof, wherein the compound has any one or more of the following features:

-   -   (I) R¹is

-   -   (II) -L¹-O-L²-Y-L³- are taken together to form a moiety selected         from the group consisting of:

-   -   (III) G is —C(O)R² or R³ wherein:         -   (A) R² is:             -   (i) C₁-C₆ alkyl optionally substituted by R^(2a), such                 as methyl, ethyl, isopropyl, or tert-butyl, each of                 which is substituted by 0-5 R^(2a) groups;             -   (ii) C₃-C₈ cycloalkyl optionally substituted by R^(2b),                 such as cyclopropyl, cyclobutyl, cyclopentyl,                 cyclohexyl, or spiro[3.3]heptanyl, each of which is                 substituted by 0-5 R^(2b) groups;             -   (iii) 3- to 12-membered heterocyclyl optionally                 substituted by R^(2c), such as 4- to 6-membered                 heterocyclyl containing 1 or 2 heteroatoms selected from                 O and N (e.g., azetidinyl, pyrrolidinyl, piperidinyl,                 oxetanyl, tetrahydrofuranyl, or tetrahydropyranyl), each                 of which is substituted by 0-5 R^(2c) groups;             -   (iv) C₆-C₁₄ aryl optionally substituted by R^(2d), such                 as phenyl substituted by 0-5 R^(2d) groups; or             -   (v) 5- to 10-membered heteroaryl optionally substituted                 by R^(2e), such as pyridinyl, pyrimidinyl, indazolyl, or                 quinolinyl, each of which is substituted by 0-5 R^(2e)                 groups; and             -   wherein each R^(2a), R^(2b), R^(2d), and R²e is                 independently R⁴, R^(2c) is oxo or R⁴, and R⁴ is                 halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to                 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered                 heteroaryl, —CN, —OR⁵, —C(O)R⁵, —C(O)OR⁵, —C(O)NR⁶R⁷,                 —NR⁵C(O)OR⁶, or —S(O)₂R⁵, wherein the C₁-C₆ alkyl, C₃-C₈                 cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl,                 and 5- to 10-membered heteroaryl of R⁴ are independently                 optionally substituted by R^(4a), wherein R^(4a) is                 halogen, —OR⁸, —NR⁸R⁹, —C(O)OR⁸, —NR⁸C(O)OR¹⁰, —CN, 5-                 to 10-membered heteroaryl, C₆-C₁₄ aryl, or C₁-C₆ alkyl,                 wherein                 -   R⁸ is hydrogen or C₁-C₆ alkyl optionally substituted                     by halogen,                 -   R⁹ is hydrogen, and                 -   R¹⁰ is C₁-C₆ alkyl optionally substituted by                     halogen; and         -   (B) R³ is:             -   (vi) C₁-C₆ alkyl optionally substituted by R^(3a), such                 as methyl or ethyl, each of which is substituted by 1                 R^(3a) group, wherein R^(3a) is phenyl or quinazolinyl;                 or             -   (vii) 5- to 10-membered heteroaryl optionally                 substituted by R³e, such as pyrimidinyl, quinazolinyl,                 or pyrazolopyrimidinyl, each of which is substituted by                 0-5 R^(3e) groups;                 In one aspect of this variation, (I) and (II) apply, and                 G is —C(O)R². In another aspect of this variation, (I)                 and (II) apply, and G is R³. In another variation, (I)                 and (II) apply, G is —C(O)R², and (i) applies. In                 another variation, (I) and (II) apply, G is —C(O)R²,                 and (ii) applies. In another variation, (I) and (II)                 apply, G is —C(O)R², and (iii) applies. In another                 variation, (I) and (II) apply, G is —C(O)R², and (iv)                 applies. In another variation, (I) and (II) apply, G is                 —C(O)R², and (v) applies. In another variation, (I)                 and (II) apply, G is R³, and (vi) applies. In another                 variation, (I) and (II) apply, G is R³, and (vii)                 applies.

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R², R² is C₁-C₆ alkyl optionally substituted by R^(2a), C₃-C₈ cycloalkyl optionally substituted by R^(2b), 3- to 12-membered heterocyclyl optionally substituted by R^(2c), C₆-C₁₄ aryl optionally substituted by R^(2d), or 5- to 10-membered heteroaryl optionally substituted by R^(2e), wherein each R^(2a), R^(2b), R^(2c), R^(2d), and R^(2e) is independently R⁴, wherein each R⁴ is independently selected from the group consisting of:

wherein each R^(4a) is independently halogen, —OR⁸, —NR⁸R⁹, —C(O)OR⁸, —NR⁸C(O)OR¹⁰, —CN, 5- to 10-membered heteroaryl, C₆-C₁₄ aryl, or C₁-C₆ alkyl, wherein R⁸, R⁹, and R¹⁰ are as defined for formula (I), and n is 0, 1, or 2. In one variation, n is 0. In another variation, n is 1. In yet another variation, n is 2.

Also provided is a compound of formula (I), or a salt thereof, wherein G is —C(O)R², R² is C₁-C₆ alkyl optionally substituted by R²a, C₃-C₈ cycloalkyl optionally substituted by R^(2b), 3- to 12-membered heterocyclyl optionally substituted by R^(2C), C₆-C₁₄ aryl optionally substituted by R^(2d), or 5- to 10-membered heteroaryl optionally substituted by R^(2e), wherein each R²a, R^(2b), R^(2C), R^(2d), and R²e is independently R⁴, wherein each R⁴ is independently selected from the group consisting of:

When a moiety is contemplated, it is understood that the moiety can be attached to the rest of the structure at any available position. For example, 3-chloro-5-methylpyridinyl may be attached to the rest of the structure at the 2-, 4-, or 6-position (i.e., 3-chloro-5-methylpyridin-2-yl, 3-chloro-5-methylpyridin-4-yl or 3-chloro-5-methylpyridin-6-yl, respectively). The R² and R³ groups described herein are shown as attached at specific positions (e.g., pyrimid-4-yl, quinazolin-4-yl, or isoquinolin-1-yl) but they can also be attached via any other available valence (e.g., pyrimid-2-yl, quinazolin-2-yl, or isoquinolin-3-yl, respectively).

Representative compounds are listed in Table 1.

TABLE 1 Compound # Structure 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

The structures in Table 1 are drawn without stereochemistry. Atoms which can be stereocenters are noted by an asterisk (*). The structures are intended to embrace all possible stereoisomers of the compound depicted, as well as mixtures of stereoisomers in any proportion. Thus, racemic mixtures, scalemic mixtures, mixtures of enantiomers in any proportion, mixtures of diastereomers in any proportion, and mixtures of enantiomers and diastereomers in any proportion are embraced, as well as individual, stereochemically pure compounds.

In some embodiments, provided is a compound selected from the compounds depicted in Table 1, or a stereoisomer thereof (including a mixture of two or more stereoisomers thereof), or a salt thereof. In some embodiments, the compound is a salt of a compound selected from the compounds depicted in Table 1, or a stereoisomer thereof.

Additional representative compounds are shown in Table 2 (FIG. 1). In some embodiments, provided is a compound selected from the compounds depicted in Table 2, or a stereoisomer thereof (including a mixture of two or more stereoisomers thereof), or a salt thereof. In some embodiments, the compound is a salt of a compound selected from the compounds depicted in Table 2, or a stereoisomer thereof. The “flat” versions of all compounds depicted in Table 2 are also contemplated in this disclosure, including flat versions of any specific stereoisomeric forms in the Table.

Regarding the structures in FIG. 1, Table 2, reference to compound numbers in the table in some instances depicts a particular stereoisomeric form of the compound number, as will be evident from the chemical structure depicted. For example, Table 2 lists

as Compound 185. It is appreciated that the compound depicted is a specific stereochemical form of Compound 185, in particular the form produced by Example 365.

In one variation, the compound detailed herein is selected from the group consisting of:

-   N-(1-methyl-1H-indazole-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(2-chloro-3-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(2-ethylbutanoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-benzoyl-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(4,4-difluorocyclohexane-1-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-pentanoyl-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(3-fluoro-5-(trifluoromethyl)benzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   2-(2-ethylbutanamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic     acid; -   2-(2-chloro-3-fluorobenzamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic     acid; -   2-(1-methyl-1H-indazole-4-carboxamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic     acid; -   2-(3-(1-methyl-1H-pyrazol-4-yl)benzamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic     acid; -   2-(2-chloro-3-fluorobenzamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic     acid; -   2-(3-(1-methyl-1H-pyrazol-4-yl)benzamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic     acid; -   N-(2-chloro-3-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-fluoro-5-(trifluoromethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   2-(2-ethylbutanamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic     acid; -   2-(1-methyl-1H-indazole-4-carboxamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic     acid; -   N-pentanoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(tert-butoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   2-((tert-butoxycarbonyl)amino)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic     acid; -   N-benzoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   2-((tert-butoxycarbonyl)amino)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic     acid; -   N-(4-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,3-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,4-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-chloro-4-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-chloro-5-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-chloro-2-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3,5-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3,4-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,3-dichlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-chloro-6-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,6-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,5-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3,4-dichlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-picolinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-nicotinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-isonicotinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-methyl-1H-indazole-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-methyl-2H-indazole-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-methyl-2H-indazole-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-methyl-1H-pyrrolo[2,3-b]pyridine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-hydroxy-2-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-ethylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-ethylpentanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-methyl-1H-pyrrolo[2,3-b]pyridine-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(3-(thiazol-5-yl)benzoyl)homoserine; -   N-(3-(hydroxymethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(quinoline-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(quinoline-7-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(quinoline-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(quinoline-8-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-(1-methyl-1H-pyrazol-4-yl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(2-hydroxy-2-phenylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-(1-methyl-1H-pyrazol-4-yl)benzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(1-phenylcyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-methyl-2-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-phenylcyclobutane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,2-dimethyl-3-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-(4-fluorophenyl)-2-methylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-methyloxetane-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-hydroxy-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-methoxy-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-methyl-2-(pyridin-3-yl)propanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,3-dihydro-1H-indene-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-cyano-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-pivaloyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,3-dihydro-1H-indene-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((neopentyloxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((1-methylcyclopropoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((1-methylcyclobutoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(((1,1,1-trifluoro-2-methylpropan-2-yl)oxy)carbonyl)homoserine; -   N-(isopropoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(diethylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(tert-butylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(tert-butyl(methyl)carbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(isopropyl(methyl)carbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(diisopropylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3,3-dimethylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-methylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-cyclobutylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-(1-methylcyclopropyl)acetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-cyclopropylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-(tert-butoxycarbonyl)-3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((3-methyl-1-(methylsulfonyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-acetyl-3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((cyclohexyloxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(isobutoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-(tert-butoxycarbonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((pyrrolidin-3-yloxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-(methylsulfonyl)butanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-(methylsulfonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-acetylpyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((1-phenylethoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((2-phenylcyclobutoxy)carbonyl)-O-(3-((5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((3-phenylcyclobutoxy)carbonyl)-O-(3-((5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((2-phenylcyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   2-((tert-butoxycarbonyl)amino)-3-methyl-4-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic     acid; -   N-(((1-(tert-butoxycarbonyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((4-phenylcyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-acetylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-acetamidopropan-2-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-((tert-butoxycarbonyl)amino)propan-2-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-(tert-butoxycarbonyl)-3-(3-chlorophenyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-(tert-butoxycarbonyl)-3-(4-isopropylphenyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((1-(tert-butoxycarbonyl)-3-(phenylethynyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(tert-butoxycarbonyl)piperidine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3,3-difluorocyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-ethyl-4,4-difluorobutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(((2-(phenylethynyl)cyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-cyclohexyl-2-methylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-(pyridin-2-yl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-ethyl-4,4,4-trifluorobutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-morpholinobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-ethyl-2-phenylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1H-pyrrolo[3,2-b]pyridine-7-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-cyanotetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(tert-butoxycarbonyl)-3-methylazetidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(tert-butoxycarbonyl)azetidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserine; -   N-(1-(methylsulfonyl)piperidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)homoserine; -   O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-7-carbonyl)homoserine; -   N-(1-methyl-4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-ethyl-4,4-difluorocyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(6-methylindoline-1-carbonyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-(((tert-butoxycarbonyl)amino)methyl)tetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(pyridin-3-ylmethyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-chloro-5-methylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(3,5-dichloroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(1-(4-(tert-butyl)phenyl)cyclobutane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3-chloro-5-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(3,5-dichloroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(bicyclo[2.2.2]octane-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-methyl-1,2,3,4-tetrahydronaphthalene-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-((methyl     sulfonyl)prolyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,4-dimethylnicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-phenyltetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-cyano-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2,4,6-trimethylpyrimidine-5-carbonyl)homoserine;     O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2,4,6-trimethylnicotinoyl)homoserine; -   N-(3-chloro-5-fluoroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(isoquinolin-1-yl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-(pyridin-2-yl)spiro[3.3]heptane-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-(1-methyl-1H-pyrazol-4-yl)tetrahydrofuran-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4,6-dimethylpyrimidine-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,6-dichloro-4-(trifluoromethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(2-fluorophenyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(benzo[d][1,3]dioxol-5-yl)cyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,2-difluoro-1-(m-tolyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1-(tetrahydro-2H-pyran-2-yl)cyclopropane-1-carbonyl)homoserine; -   N-(4-methoxy-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-acetyl-4-(trifluoromethyl)piperidine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2,3-dihydrobenzo[b][1,4]dioxine-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(1-(3-chlorobenzyl)cyclopentane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1-(3-(trifluoromethoxy)phenyl)cyclopropane-1-carbonyl)homoserine; -   N-(4-fluoro-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-cyanotetrahydro-2H-pyran-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserine; -   N-(quinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(8-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(7-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(7-methylquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(6-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(5-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(6-methylquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(6-(tert-butyl)-2-phenylpyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(6-(tert-butyl)pyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(2-(tert-butyl)pyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(4-(tert-butyl)pyrimidin-2-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; -   N-(8-oxabicyclo[3.2.1]octane-3-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(2-(dimethylamino)-3,5-dimethylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(5-chloro-2-(dimethylamino)-3-methylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(3-cyclopropyl-5-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(4-((1,3-dimethyl-1H-pyrazol-5-yl)methyl)-2,6-dimethylbenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserin;     e -   N-(5-chloro-2-methoxy-3-methylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(3-ethyl-5-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(4-((1,3-dimethyl-1H-pyrazol-5-yl)methyl)-2-fluoro-6-methylbenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(3-chloro-5-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(5-fluoro-3-methylpyridazine-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(2,4-dimethyl-6-oxo-1-(2,2,2-trifluoroethyl)-1,6-dihydropyridine-3-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(3,5-dimethylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(3,5-dimethylpyridazine-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-N-(1,2,4-trimethyl-6-oxo-1,6-dihydropyridine-3-carbonyl)homoserine; -   N-(4-cyano-2-fluoro-6-methylbenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(3,5-dimethylmorpholine-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(5-chloro-3-methylpyridazine-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(6-methoxy-2,4-dimethylnicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; -   N-(2-chloro-4-cyano-6-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine;     and -   N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine.

In one variation, the compound detailed herein is selected from the group consisting of: N-(2-chloro-3-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(1-methyl-1H-indazole-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(4,4-difluorocyclohexane-1-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-pentanoyl-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(3-fluoro-5-(trifluoromethyl)benzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(3-fluoro-5-(trifluoromethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-pentanoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(4-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,4-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-chloro-4-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-chloro-5-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-chloro-2-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,5-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-dichlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-chloro-6-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,6-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,5-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,4-dichlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-picolinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-nicotinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-methyl-1H-indazole-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-2H-indazole-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-2H-indazole-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-methyl-1H-pyrrolo[2,3-b]pyridine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-ethylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-methyl-1H-pyrrolo[2,3-b]pyridine-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-(hydroxymethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinoline-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinoline-7-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinoline-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinoline-8-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-isonicotinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-ethylpentanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-chloro-3-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,4-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-ethylpentanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-isonicotinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(3-(thiazol-5-yl)benzoyl)homoserine; N-(3-hydroxy-2-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-(1-methyl-1H-pyrazol-4-yl)benzoyl)-O-(3-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)cyclobutyl)homoserine; N-(3-(1-methyl-1H-pyrazol-4-yl)benzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2-hydroxy-2-phenylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-phenylcyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-2-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-phenylcyclobutane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,2-dimethyl-3-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(tert-butoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(4-fluorophenyl)-2-methylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-methyloxetane-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-hydroxy-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-methoxy-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-2-(pyridin-3-yl)propanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-dihydro-1H-indene-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-cyano-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-pivaloyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-dihydro-1H-indene-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((neopentyloxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((1-methylcyclopropoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((1-methylcyclobutoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(((1,1,1-trifluoro-2-methylpropan-2-yl)oxy)carbonyl)homoserine; N-(isopropoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(diethylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(tert-butylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(tert-butyl(methyl)carbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(isopropyl(methyl)carbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(diisopropylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,3-dimethylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-methylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-cyclobutylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(1-methylcyclopropyl)acetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-cyclopropylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)-3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((3-methyl-1-(methylsulfonyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-acetyl-3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((cyclohexyloxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(isobutoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((pyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-(methylsulfonyl)butanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(methyl sulfonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-acetylpyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((1-phenylethoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((2-phenylcyclobutoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((3-phenylcyclobutoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; 2-((tert-butoxycarbonyl)amino)-3-methyl-4-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic acid; N-(((2-phenylcyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((4-phenylcyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-acetylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-((tert-butoxycarbonyl)amino)propan-2-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-acetamidopropan-2-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(((1-(tert-butoxycarbonyl)-3-(3-chlorophenyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)-3-(4-isopropylphenyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)-3-(phenylethynyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(tert-butoxycarbonyl)piperidine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,3-difluorocyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-ethyl-4,4-difluorobutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(((2-(phenylethynyl)cyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-cyclohexyl-2-methylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(pyridin-2-yl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-ethyl-4,4,4-trifluorobutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-morpholinobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-ethyl-2-phenylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1H-pyrrolo[3,2-b]pyridine-7-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-cyanotetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(tert-butoxycarbonyl)-3-methylazetidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(tert-butoxycarbonyl)azetidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(methylsulfonyl)piperidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-7-carbonyl)homoserine; N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl) homoserine; N-(1-methyl-4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(1-ethyl-4,4-difluorocyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(6-methylindoline-1-carbonyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-(((tert-butoxycarbonyl)amino)methyl)tetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(pyridin-3-ylmethyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-chloro-5-methylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(3,5-dichloroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(1-(4-(tert-butyl)phenyl)cyclobutane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserine; N-(3-chloro-5-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,5-dichloroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(bicyclo[2.2.2]octane-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-1,2,3,4-tetrahydronaphthalene-2-carbonyl)-O-(3-(2(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((methylsulfonyl)prolyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,4-dimethylnicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-phenyltetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-cyano-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2,4,6-trimethylpyrimidine-5-carbonyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2,4,6-trimethylnicotinoyl)homoserine; N-(3-chloro-5-fluoroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(isoquinolin-1-yl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(pyridin-2-yl)spiro[3.3]heptane-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(1-methyl-1H-pyrazol-4-yl)tetrahydrofuran-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4,6-dimethylpyrimidine-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,6-dichloro-4-(trifluoromethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(2-fluorophenyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(benzo[d][1,3]dioxol-5-yl)cyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,2-difluoro-1-(m-tolyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1-(tetrahydro-2H-pyran-2-yl)cyclopropane-1-carbonyl)homoserine; N-(4-methoxy-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-acetyl-4-(trifluoromethyl)piperidine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-dihydrobenzo[b][1,4]dioxine-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(3-chlorobenzyl)cyclopentane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1-(3-(trifluoromethoxy)phenyl)cyclopropane-1-carbonyl)homoserine; N-(4-fluoro-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(tert-butyl)pyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-(tert-butyl)pyrimidin-2-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(quinazolin-4-yl)homoserine; N-(6-(tert-butyl)pyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; 2-[(4-amino-2,6-dichloro-benzoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(4-chloro-2,6-dimethylnicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-[(3-chloro-6-methyl-pyridine-2-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(2,6-dimethylpiperidine-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,5-dimethylpyrrolidine-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,6-dichloro-4-cyanobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,6-dichloro-3-nitrobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]-2-[(1,2,4-trimethyl-6-oxo-pyridine-3-carbonyl)amino]butanoic acid; N-(2-chloro-4-cyano-6-methylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-bromo-5-chloro-2-fluoroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(5,6,7,8-tetrahydronaphthalene-1-carbonyl)-homoserine; N-(3-bromo-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-[(3-chloro-5-methoxy-pyridine-4-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2,6-dichloro-4-fluoro-benzoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2-chloro-6-fluoro-benzoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(3-bromo-2-chloro-6-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,4-dimethyl-6-oxo-1-phenyl-1,6-dihydropyridine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(5-bromo-2-hydroxyisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-cyclopropylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-ethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-cyano-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-bromo-5-fluoroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-methoxy-3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-(trifluoromethyl)isonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-bromo-5-chloroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-(dimethylamino)-3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-fluoro-2-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,6-dichloro-3-cyanobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-methyl-5-(trifluoromethyl)isonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-hydroxy-3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-cyano-2-hydroxy-6-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(5-chloro-3-fluoro-2-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-[(6-methoxy-2,4-dimethyl-pyridine-3-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[2,6-dimethyl-4-[(4-methylpiperazin-1-yl)methyl]benzoyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(3,5-dimethylmorpholine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-[[5-chloro-3-fluoro-2-[(4-methylpiperazin-1-yl)methyl]pyridine-4-carbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; methyl 2-[(7-chloro-5-oxo-2,3-dihydro-1H-indolizine-8-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoate; 2-[(2,6-difluoro-4-hydroxy-benzoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(4-chloro-2-methyl-pyrazole-3-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2-methylpyrazole-3-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(1-(phenylsulfonyl)piperidine-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-(3,3-dimethylbutanoylamino)-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2-phenylacetyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]-2-[(4,4,4-trifluoro-3,3-dimethyl-butanoyl)amino]butanoic acid; 2-[(4,4-difluoro-3,3-dimethyl-butanoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[2-phenylpropanoyl]amino]-4-[3- [2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[2-(3,5-difluorophenyl)acetyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[2-(tert-butoxycarbonylamino)-1-methyl-ethoxy]carbonylamino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(3,6-dimethylpyridine-2-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(6-fluorochromane-2-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]-2-[2-[3-(trifluoromethyl)phenyl]butanoylamino]butanoic acid; 2-[(3-chloro-5-methyl-pyridine-4-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(4-cyano-2,6-dimethyl-benzoyl)amino]-4-[3- [2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[4-(2-chlorophenyl)tetrahydropyran-4-carbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2-hydroxyindane-2-carbonyl)amino]-4-[3- [2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(1-cyclopropylcyclopropanecarbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[3-(difluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridine-6-carbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(1-cyclopropylcyclobutanecarbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[1-(4-isopropylphenyl)cyclopentanecarbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-(bicyclo[2.2.2]octane-4-carbonylamino)-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-(3,4,5,6,7,7a-hexahydro-2H-benzofuran-3a-carbonylamino)-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[1-(2-phenylethyl)cyclopropanecarbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[4-(3-methylisoxazol-5-yl)tetrahydropyran-4-carbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[1-(benzenesulfonyl)cyclopropanecarbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(1-phenylcycloheptanecarbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(4-methylsulfonyltetrahydropyran-4-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[1-(4-sulfamoylphenyl)cyclopropanecarbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-((phenylsulfonyl)prolyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(5-chloro-3-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-(pyrimidin-4-ylamino)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic acid; 2-[(3-chloro-5-methyl-pyridine-4-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(2,4-dimethylpyridine-3-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(4-cyano-2,6-dimethyl-benzoyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(3,5-dichloropyridine-4-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; N-(3,5-dimethylmorpholine-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(3,5-dimethylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; 2-[(2,4-dichloro-6-fluoro-benzoyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(2,4-dimethyl-6-oxo-1H-pyridine-3-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; N-(3-chloro-5-methoxyisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; 2-[(2-chloro-6-fluoro-benzoyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(5-bromo-2-hydroxyisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(3-bromo-5-chloro-2-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2,4-dimethyl-6-oxo-1-phenyl-1,6-dihydropyridine-3-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-N-(5,6,7,8-tetrahydronaphthalene-1-carbonyl)-homoserine; N-(3-bromo-2,6-dimethylbenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(3-chloro-5-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(3-bromo-2-chloro-6-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; 2-[(3-chloro-5-methoxy-pyridine-4-carbonyl)amino]-4-[2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]-4-[2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; N-(3-chloro-5-fluoroisonicotinoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2,6-dichlorobenzoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2-chloro-6-fluorobenzoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(4-fluoro-2-methylnicotinoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; 2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]-4-[2-hydroxy-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-(1-methyl-1H-indazole-4-carboxamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic acid; 2-(3-(1-methyl-1H-pyrazol-4-yl)benzamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic acid; 2-(2-chloro-3-fluorobenzamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic acid; 2-(3-(1-methyl-1H-pyrazol-4-yl)benzamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic acid; 2-(2-ethylbutanamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic acid; 2-(1-methyl-1H-indazole-4-carboxamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic acid; 2-((tert-butoxycarbonyl)amino)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic acid; N-benzoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(8-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(7-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(7-methylquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(6-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(5-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(6-methylquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; and N-(6-(tert-butyl)-2-phenylpyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine.

In some embodiments, a composition, such as a pharmaceutical composition, is provided wherein the composition comprises a compound selected from the group consisting of one or more of the compounds depicted in Table 1, or a stereoisomer thereof (including a mixture of two or more stereoisomers thereof), or a salt thereof. In some embodiments, the composition comprises a compound selected from the group consisting of a salt of one or more of the compounds depicted in Table 1. In one aspect, the composition is a pharmaceutical composition that further comprises a pharmaceutically acceptable carrier.

In some embodiments, a composition, such as a pharmaceutical composition, is provided wherein the composition comprises a compound selected from the group consisting of one or more of the compounds depicted in Table 2, or a stereoisomer thereof (including a mixture of two or more stereoisomers thereof), or a salt thereof. In some embodiments, the composition comprises a compound selected from the group consisting of a salt of one or more of the compounds depicted in Table 2. In one aspect, the composition is a pharmaceutical composition that further comprises a pharmaceutically acceptable carrier.

The invention also includes all salts of compounds referred to herein, such as pharmaceutically acceptable salts. The invention also includes any or all of the stereochemical forms, including any enantiomeric or diastereomeric forms, and any tautomers or other forms of the compounds described. Unless stereochemistry is explicitly indicated in a chemical structure or name, the structure or name is intended to embrace all possible stereoisomers of a compound depicted. In addition, where a specific stereochemical form is depicted, it is understood that other stereochemical forms are also described and embraced by the invention. All forms of the compounds are also embraced by the invention, such as crystalline or non-crystalline forms of the compounds. It is also understood that prodrugs, solvates and metabolites of the compounds are embraced by this disclosure. Compositions comprising a compound of the invention are also intended, such as a composition of substantially pure compound, including a specific stereochemical form thereof. Compositions comprising a mixture of compounds of the invention in any ratio are also embraced by the invention, including mixtures of two or more stereochemical forms of a compound of the invention in any ratio, such that racemic, non-racemic, enantioenriched and scalemic mixtures of a compound are embraced. Where one or more tertiary amine moiety is present in the compound, the N-oxides are also provided and described.

Compounds described herein are αvβ6 integrin inhibitors. In some instances, it is desirable for the compound to inhibit other integrins in addition to αvβ6 integrin. In some embodiments, the compound inhibits αvβ6 integrin and one or more of αvβ1, αvβ3, αvβ5, α2β1, α3β1, α6β1 integrin, α7β1 and α11β1. In some embodiments, the compound inhibits αvβ6 integrin and αvβ1 integrin. In some embodiments, the compound inhibits αvβ6 integrin, αvβ3 integrin and αvβ5 integrin. In some embodiments, the compound inhibits αvβ6 integrin and α2β1 integrin. In some embodiments, the compound inhibits αvβ6 integrin, α2β1 integrin and α3β1 integrin. In some embodiments, the compound inhibits αvβ6 integrin and α6β1 integrin. In some embodiments, the compound inhibits αvβ6 integrin and α7β3 integrin. In some embodiments, the compound inhibits αvβ6 integrin and α11β1 integrin.

In some instances, it is desirable to avoid inhibition of other integrins. In some embodiments, the compound is a selective αvβ6 integrin inhibitor. In some embodiments, the compound does not inhibit substantially α4β1, αvβ8 and/or α2β3 integrin. In some embodiments, the compound inhibits αvβ6 integrin but does not inhibit substantially α4β1 integrin. In some embodiments, the compound inhibits αvβ6 integrin but does not inhibit substantially αvβ8 integrin. In some embodiments, the compound inhibits αvβ6 integrin but does not inhibit substantially α2β3 integrin. In some embodiments, the compound inhibits αvβ6 integrin but does not inhibit substantially the αvβ8 integrin and the α4β1 integrin.

The invention also intends isotopically-labeled and/or isotopically-enriched forms of compounds described herein. The compounds herein may contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. In some embodiments, the compound is isotopically-labeled, such as an isotopically-labeled compound of the formula (I) or variations thereof described herein, where one or more atoms are replaced by an isotope of the same element. Exemplary isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, chlorine, such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C ¹³N, ¹⁵O, ¹⁷O, ³²P, ³⁵S, ¹⁸F, ³⁶Cl. Incorporation of heavier isotopes such as deuterium (²H or D) can afford certain therapeutic advantages resulting from greater metabolic stability, for example, increased in vivo half-life, or reduced dosage requirements and, hence may be preferred in some instances. In some embodiments, provided herein is an isotopically enriched form of any of the formulae described herein, wherein the compound comprises one or more deuterium atoms. In some embodiments, the compounds of formula (I) may have one or more of the hydrogen atoms replaced by deuterium, such as any of the hydrogens in one or more of the moieties G, L¹, L², Y, L³, and R¹.

Isotopically-labeled compounds of the present invention can generally be prepared by standard methods and techniques known to those skilled in the art or by procedures similar to those described in the accompanying Examples substituting appropriate isotopically-labeled reagents in place of the corresponding non-labeled reagent.

The invention also includes any or all metabolites of any of the compounds described. The metabolites may include any chemical species generated by a biotransformation of any of the compounds described, such as intermediates and products of metabolism of the compound.

Articles of manufacture comprising a compound of the invention, or a salt or solvate thereof, in a suitable container are provided. The container may be a vial, jar, ampoule, preloaded syringe, i.v. bag, and the like.

Preferably, the compounds detailed herein are orally bioavailable. However, the compounds may also be formulated for parenteral (e.g., intravenous) administration.

One or several compounds described herein can be used in the preparation of a medicament by combining the compound or compounds as an active ingredient with a pharmacologically acceptable carrier, which are known in the art. Depending on the therapeutic form of the medication, the carrier may be in various forms.

General Synthetic Methods

The compounds of the invention may be prepared by a number of processes as generally described below and more specifically in the Examples hereinafter (such as the schemes provides in the Examples below). In the following process descriptions, the symbols when used in the formulae depicted are to be understood to represent those groups described above in relation to the formulae herein.

Where it is desired to obtain a particular stereoisomer of a compound, this may be accomplished from a corresponding mixture of stereoisomers using any suitable conventional procedure for separating stereoisomers or resolving enantiomers. Thus, for example, diastereomeric derivatives may be produced by reaction of a mixture of enantiomers, e.g., a racemate, and an appropriate chiral compound. The diastereomers may then be separated by any convenient means, for example by crystallization, and the desired enantiomer recovered. In another resolution process, a racemate may be separated using chiral High Performance Liquid Chromatography. Alternatively, if desired a particular stereoisomer may be obtained by using an appropriate chiral intermediate in one of the processes described.

Chromatography, recrystallization and other conventional separation procedures may also be used with intermediates or final products where it is desired to obtain a particular isomer of a compound or to otherwise purify a product of a reaction.

Solvates and/or polymorphs of a compound provided herein or a pharmaceutically acceptable salt thereof are also contemplated. Solvates contain either stoichiometric or non-stoichiometric amounts of a solvent, and are often formed during the process of crystallization. Hydrates are formed when the solvent is water, or alcoholates are formed when the solvent is alcohol. Polymorphs include the different crystal packing arrangements of the same elemental composition of a compound. Polymorphs usually have different X-ray diffraction patterns, infrared spectra, melting points, density, hardness, crystal shape, optical and electrical properties, stability, and/or solubility. Various factors such as the recrystallization solvent, rate of crystallization, and storage temperature may cause a single crystal form to dominate.

Compounds provided herein may be prepared according to General Schemes A, B, C, D-2, E-2, F-2, G-2, and H; Schemes D-1, E-1, F-1, and G-1; General Procedures A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, and R; and Examples 1-226.

Compounds of formula 18A can be prepared according to General Scheme A, wherein G, R², and R³ are as defined for formula (I), or any applicable variations detailed herein; X¹ is a leaving group (e.g., —OH, —Cl,

and the like); and X² is another leaving group (e.g., —Cl, —Br, —I, —OTf, and the like).

Silylation of compound 1A gives compound 2A, which can be reduced with a suitable reducing agent to give compound 3A. Iodination of 3A gives compound 4A, which can be alkylated with compound 5A under basic conditions to give compound 6A. Condensation of compound 6A with compound 7A in the presence of an appropriate catalyst gives compound 8A, which can be alkylated with an alkyl halide to give compound 9A. Oxidative cleavage of 9A gives compound 10A, which can be treated with compound 11A under basic conditions to afford compound 12A. Reduction of compound 12A gives compound 13A, which can be exposed to an appropriate acid to give compound 14A. Coupling of compound 14A with compound of formula 15A or 16A gives rise to compound 17A, which can be hydrolyzed in the presence of a suitable hydroxide source to give compound 18A.

Reaction conditions for the transformations of General Scheme A are provided in the General Procedures that follow, in particular General Procedures D, E, F, H, I, K, and N. Exemplary reaction conditions for the transformations of General Scheme A are provided in General Procedure A, omitting the chiral separation step at the end of General Procedure A.

Compounds of formula 18B can be prepared according to General Scheme B, wherein G, R², and R³ are as defined for formula (I), or any applicable variations detailed herein; X¹ is a leaving group (e.g., —OH, —Cl,

and the like); and X² is another leaving group (e.g., —Cl, —Br, —I, —OTf, and the like).

Silylation of compound 1B gives compound 2B, which can be reduced with a suitable reducing agent to give compound 3B. Iodination of 3B gives compound 4B, which can be alkylated with compound 5A under basic conditions to give compound 6B. Condensation of compound 6B with compound 7A in the presence of an appropriate catalyst gives compound 8B, which can be alkylated with an alkyl halide to give compound 9B. Oxidative cleavage of 9B gives compound 10B, which can be treated with compound 11A under basic conditions to afford compound 12B. Reduction of compound 12B gives compound 13B, which can be exposed to an appropriate acid to give compound 14B. Coupling of compound 14B with compound of formula 15A or 16A gives rise to compound 17B, which can be hydrolyzed in the presence of a suitable hydroxide source to give compound 18B.

Reaction conditions for the transformations of General Scheme B are provided in the General Procedures that follow in particular General Procedures D, E, F, H, I, K, and N. Exemplary reaction conditions for the transformations of General Scheme B are provided in General Procedure B, omitting the chiral separation step at the end of General Procedure B.

Compounds of formula 12C can be prepared according to General Scheme C, wherein G, R² and R³ are as defined for formula (I), or any applicable variations detailed herein; X¹ is a leaving group (e.g., —OH, —Cl,

and the like); and X² is another leaving group (e.g., —Cl, —Br, —I, —OTf, and the like).

Reduction of compound 1C gives compound 2C, which can be alkylated with an alkyl halide to give compound 3C. Oxidative cleavage of 3C gives compound 4C, which can be treated with compound 11A under basic conditions to afford compound 6C. Reduction of compound 6C gives compound 7C, which can be exposed to an appropriate acid to give compound 8C. Coupling of compound 8C with compound of formula 15A or 16A gives rise to compound of formula 11C, which can be hydrolyzed in the presence of a suitable hydroxide source to give compound 12C.

Reaction conditions for the transformations of General Scheme C are provided in the General Procedures that follow, in particular General Procedures D, E, F, H, I, K, and N. Exemplary reaction conditions for the transformations of General Scheme C are provided in General Procedure C, omitting the chiral separation step at the end of General Procedure C.

Compounds of formula 18D can be prepared according to Scheme D-1 followed by General Scheme D-2, wherein G, R² and R³ are as defined for formula (I), or any applicable variations detailed herein; X¹ is a leaving group (e.g., —OH, —Cl,

and the like); and X² is another leaving group (e.g., —Cl, —Br, —I, —OTf, and the like).

Silylation of compound 1A gives compound 2A, which can be reduced with a suitable reducing agent to give compound 3A. Iodination of 3A gives compound 4A, which can be alkylated with compound 5A under basic conditions to give compound 6A. Condensation of compound 6A with compound 7A in the presence of an appropriate catalyst gives compound 8A, which can be alkylated with an alkyl halide to give compound 9A. Oxidative cleavage of 9A gives compound 10A, which can be treated with compound 11A under basic conditions to afford compound 12A. Reduction of compound 12A gives compound 13A, which can be separated using chiral SFC to afford Isomer D1 and Isomer D2.

Exposure of Isomer D1 (i.e., first eluting isomer from Scheme D-1) or Isomer D2 (i.e., second eluting isomer from Scheme D-1) to an appropriate acid gives compound 14D, wherein the wavy line in compound 14D refers to the isomer obtained when either Isomer D1 or Isomer D2 is reacted. Coupling of compound 14D with compound of formula 15A or 16A gives rise to compound 17D, which can be hydrolyzed in the presence of a suitable hydroxide source to give compound 18D.

Reaction conditions for the transformations of General Scheme D-2 are provided in the General Procedures that follow, in particular General Procedures D, E, F, H, I, K, and N. Exemplary reaction conditions for the transformations of Scheme D-1 are provided in General Procedure A.

Compounds of formula 18E can be prepared according to Scheme E-1 followed by General Scheme E-2, wherein G, R² and R³ are as defined for formula (I), or any applicable variations detailed herein; X¹ is a leaving group (e.g., —OH, —Cl,

and the like); and X² is another leaving group (e.g., —Cl, —Br, —I, —OTf, and the like).

Silylation of compound 1B gives compound 2B, which can be reduced with a suitable reducing agent to give compound 3B. Iodination of 3B gives compound 4B, which can be alkylated with compound 5A under basic conditions to give compound 6B. Condensation of compound 6B with compound 7A in the presence of an appropriate catalyst gives compound 8B, which can be alkylated with an alkyl halide to give compound 9B. Oxidative cleavage of 9B gives compound 10B, which can be treated with compound 11A under basic conditions to afford compound 12B. Reduction of compound 12B gives compound 13B, which can be separated via supercritical fluid chromatography (SFC) into Isomer E1 and Isomer E2.

Exposure of Isomer E1 (i.e., first eluting isomer from Scheme E-1) or Isomer E2 (i.e., second eluting isomer from Scheme E-1) to an appropriate acid gives compound 14E, wherein the wavy line in compound 14E refers to the isomer obtained when either Isomer E1 or Isomer E2 is reacted. Coupling of compound 14E with compound of formula 15A or 16A gives rise to compound 17E, which can be hydrolyzed in the presence of a suitable hydroxide source to give compound 18E.

Reaction conditions for the transformations of General Scheme E-2 are provided in the General Procedures that follow, in particular General Procedures D, E, F, H, I, K, and N. Exemplary reaction conditions for the transformations of Scheme E-1 are provided in General Procedure B.

Compounds of formula 12F can be prepared according to Scheme F-1 followed by General Scheme F-2, wherein G, R² and R³ are as defined for formula (I), or any applicable variations detailed herein; X¹ is a leaving group (e.g., —OH, —Cl,

and the like); and X² is another leaving group (e.g., —Cl, —Br, —I, —OTf, and the like).

Reduction of compound 1C gives compound 2C, which can be alkylated with an alkyl halide to give compound 3C. Oxidative cleavage of 3C gives compound 4C, which can be treated with compound 11A under basic conditions to afford compound 6C. Reduction of compound 6C gives compound 7C, which can be separated via supercritical fluid chromatography (SFC) into Isomer F1 and Isomer F2.

Exposure of Isomer F1 (i.e., first eluting isomer from Scheme F-1) or Isomer F2 (i.e., second eluting isomer from Scheme F-1) to an appropriate acid gives compound 8F, wherein the wavy line in compound 8F refers to the isomer obtained when either Isomer F1 or Isomer F2 is reacted. Coupling of compound 8F with compound of formula 15A or 16A gives rise to compound of formula 11F, which can be hydrolyzed in the presence of a suitable hydroxide source to give compound 12F.

Reaction conditions for the transformations of General Scheme F-2 are provided in the General Procedures that follow, in particular General Procedures D, E, F, H, I, K, and N. Exemplary reaction conditions for the transformations of Scheme F-1 are provided in General Procedure C.

Compounds of formula 18G can be prepared according to Scheme G-1 followed by General Scheme G-2, wherein G, R² and R³ are as defined for formula (I), or any applicable variations detailed herein; X¹ is a leaving group (e.g., —OH, —Cl,

and the like); and X² is another leaving group (e.g., —Cl, —Br, —I, —OTf, and the like).

Silylation of compound 1A gives compound 2A, which can be reduced with a suitable reducing agent to give compound 3A. Iodination of 3A gives compound 4A, which can be alkylated with compound 5A under basic conditions to give compound 6A. Condensation of compound 6A with compound 7A in the presence of an appropriate catalyst gives compound 8A, which can be alkylated with an alkyl halide to give compound 9A. Oxidative cleavage of 9A gives compound 10A, which can be treated with compound 11A under basic conditions to afford compound 12A. Reduction of compound 12A gives compound 13A, which can be exposed to an appropriate acid to give compound 14A. Compound 14A can be separated using chiral SFC to afford Isomer G1 and Isomer G2.

Coupling of Isomer G1 (i.e., first eluting isomer from Scheme G-1) or Isomer G2 (i.e., second eluting isomer from Scheme G-1) with compound of formula 15A or 16A gives compound 17G, wherein the wavy line in compound 17G refers to the isomer obtained when either Isomer G1 or Isomer G2 is reacted. Compound 17G can be hydrolyzed in the presence of a suitable hydroxide source to give compound 18G.

Reaction conditions for the transformations of Scheme G-1 and General Scheme G-2 are provided in the General Procedures that follow, in particular General Procedures D, E, F, H, I, K, and N. Exemplary reaction conditions for the transformations of Scheme G-1 are provided in General Procedure A.

Compounds of formula 18H can be prepared according to General Scheme H, wherein G, R² and R³ are as defined for formula (I), or any applicable variations detailed herein; X¹ is a leaving group (e.g., —OH, —Cl,

and the like); and X² is another leaving group (e.g., —Cl, —Br, —I, —OTf, and the like).

Allylation of compound 1A gives compound 2H, which can be reduced with a suitable reducing agent to give compound 3H. Iodination of 3H gives compound 4H, which can be alkylated with compound 5A under basic conditions to give compound 6H. Condensation of compound 6H with compound 7A in the presence of an appropriate catalyst gives compound 9H, which can be alkylated with an alkyl halide to give compound 9H. Oxidative cleavage of 9H followed by treating with compound 11A under basic conditions affords compound 12H. Reduction of compound 12H gives compound 13H, which can be exposed to an appropriate acid to give compound 14H. Coupling of compound 14H with compound of formula 15A or 16A gives rise to compound 17H, which can be hydrolyzed in the presence of a suitable hydroxide source to give compound 18H.

Reaction conditions for the transformations of General Scheme H are provided in the General Procedures that follow, in particular General Procedures D, E, F, H, I, K, and N.

It is understood that the schemes above may be modified to arrive at various compounds of the invention by selection of appropriate reagents and starting materials. For a general description of protecting groups and their use, see P.G.M. Wuts and T.W. Greene, Greene's Protective Groups in Organic Synthesis 4^(th) edition, Wiley-Interscience, New York, 2006.

Additional methods of preparing compounds according to formula (I), and salts thereof, are provided in the Examples. As a skilled artisan would recognize, the methods of preparation taught herein may be adapted to provide additional compounds within the scope of formula (I), for example, by selecting starting materials which would provide a desired compound.

Pharmaceutical Compositions and Formulations

Pharmaceutical compositions of any of the compounds detailed herein, including compounds of the formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), and (Vb-2), or a salt thereof, or compounds depicted in Table 1, or a salt thereof, or mixtures thereof, are embraced by this invention. Thus, the invention includes pharmaceutical compositions comprising a compound of the invention or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or excipient. In one aspect, the pharmaceutically acceptable salt is an acid addition salt, such as a salt formed with an inorganic or organic acid. Pharmaceutical compositions according to the invention may take a form suitable for oral, buccal, parenteral, nasal, topical or rectal administration or a form suitable for administration by inhalation. In one embodiment, the pharmaceutical composition are prepared from mixtures of any of the compounds detailed herein, or salts thereof. In one embodiment, the pharmaceutical composition is a composition for controlled release of any of the compounds detailed herein.

Pharmaceutical compositions of any of the compounds detailed herein, including compounds of the formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound of Table 1 or Table 2, or any one of compounds 1-329; or a salt thereof, or mixtures thereof, are also embraced by this invention.

A compound as detailed herein may in one aspect be in a purified form and compositions comprising a compound in purified forms are detailed herein. In one embodiment, compositions may have no more than 35% impurity, wherein the impurity denotes a compound other than the compound comprising the majority of the composition or a salt thereof, for example, a composition of a compound selected from a compound of Table 1 may contains no more than 35% impurity, wherein the impurity denotes a compound other than the compound of Table 1 or a salt thereof. In one embodiment, compositions may contain no more than 25% impurity. In one embodiment, compositions may contains no more than 20% impurity. In still further embodiments, compositions comprising a compound as detailed herein or a salt thereof are provided as compositions of substantially pure compounds. “Substantially pure” compositions comprise no more than 10% impurity, such as a composition comprising less than 9%, 7%, 5%, 3%, 1%, or 0.5% impurity. In some embodiments, a composition containing a compound as detailed herein or a salt thereof is in substantially pure form. In still another variation, a composition of substantially pure compound or a salt thereof is provided wherein the composition contains or no more than 10% impurity. In a further variation, a composition of substantially pure compound or a salt thereof is provided wherein the composition contains or no more than 9% impurity. In a further variation, a composition of substantially pure compound or a salt thereof is provided wherein the composition contains or no more than 7% impurity. In a further variation, a composition of substantially pure compound or a salt thereof is provided wherein the composition contains or no more than 5% impurity. In another variation, a composition of substantially pure compound or a salt thereof is provided wherein the composition contains or no more than 3% impurity. In still another variation, a composition of substantially pure compound or a salt thereof is provided wherein the composition contains or no more than 1% impurity. In a further variation, a composition of substantially pure compound or a salt thereof is provided wherein the composition contains or no more than 0.5% impurity. In yet other variations, a composition of substantially pure compound means that the composition contains no more than 10% or preferably no more than 5% or more preferably no more than 3% or even more preferably no more than 1% impurity or most preferably no more than 0.5% impurity, which impurity may be the compound in a different stereochemical form. For instance, a composition of substantially pure (S) compound means that the composition contains no more than 10% or no more than 5% or no more than 3% or no more than 1% or no more than 0.5% of the (R) form of the compound.

In further embodiments, the purified forms and substantially pure forms of the compounds apply to any compounds of the formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound of Table 1 or Table 2, or any one of compounds 1-329

In one variation, the compounds herein are synthetic compounds prepared for administration to an individual such as a human. In another variation, compositions are provided containing a compound in substantially pure form. In another variation, the invention embraces pharmaceutical compositions comprising a compound detailed herein and a pharmaceutically acceptable carrier or excipient. In another variation, methods of administering a compound are provided. The purified forms, pharmaceutical compositions and methods of administering the compounds are suitable for any compound or form thereof detailed herein.

The compound detailed herein or salt thereof may be formulated for any available delivery route, including an oral, mucosal (e.g., nasal, sublingual, vaginal, buccal or rectal), parenteral (e.g., intramuscular, subcutaneous or intravenous), topical or transdermal delivery form. A compound or salt thereof may be formulated with suitable carriers to provide delivery forms that include, but are not limited to, tablets, caplets, capsules (such as hard gelatin capsules or soft elastic gelatin capsules), cachets, troches, lozenges, gums, dispersions, suppositories, ointments, cataplasms (poultices), pastes, powders, dressings, creams, solutions, patches, aerosols (e.g., nasal spray or inhalers), gels, suspensions (e.g., aqueous or non-aqueous liquid suspensions, oil-in-water emulsions or water-in-oil liquid emulsions), solutions and elixirs.

One or several compounds described herein or a salt thereof can be used in the preparation of a formulation, such as a pharmaceutical formulation, by combining the compound or compounds, or a salt thereof, as an active ingredient with a pharmaceutically acceptable carrier, such as those mentioned above. Depending on the therapeutic form of the system (e.g., transdermal patch vs. oral tablet), the carrier may be in various forms. In addition, pharmaceutical formulations may contain preservatives, solubilizers, stabilizers, re-wetting agents, emulgators, sweeteners, dyes, adjusters, and salts for the adjustment of osmotic pressure, buffers, coating agents or antioxidants. Formulations comprising the compound may also contain other substances which have valuable therapeutic properties. Pharmaceutical formulations may be prepared by known pharmaceutical methods. Suitable formulations can be found, e.g., in Remington: The Science and Practice of Pharmacy, Lippincott Williams & Wilkins, 21^(st) ed. (2005), which is incorporated herein by reference.

Compounds as described herein may be administered to individuals (e.g., a human) in a form of generally accepted oral compositions, such as tablets, coated tablets, and gel capsules in a hard or in soft shell, emulsions or suspensions. Examples of carriers, which may be used for the preparation of such compositions, are lactose, corn starch or its derivatives, talc, stearate or its salts, etc. Acceptable carriers for gel capsules with soft shell are, for instance, plant oils, wax, fats, semisolid and liquid poly-ols, and so on. In addition, pharmaceutical formulations may contain preservatives, solubilizers, stabilizers, re-wetting agents, emulgators, sweeteners, dyes, adjusters, and salts for the adjustment of osmotic pressure, buffers, coating agents or antioxidants.

Any of the compounds described herein can be formulated in a tablet in any dosage form described, for example, a compound as described herein or a pharmaceutically acceptable salt thereof can be formulated as a 10 mg tablet.

Compositions comprising a compound provided herein are also described. In one variation, the composition comprises a compound and a pharmaceutically acceptable carrier or excipient. In another variation, a composition of substantially pure compound is provided. In some embodiments, the composition is for use as a human or veterinary medicament. In some embodiments, the composition is for use in a method described herein. In some embodiments, the composition is for use in the treatment of a disease or disorder described herein.

Methods of Use

Compounds and compositions of the invention, such as a pharmaceutical composition containing a compound of any formula provided herein or a salt thereof and a pharmaceutically acceptable carrier or excipient, may be used in methods of administration and treatment as provided herein. The compounds and compositions may also be used in in vitro methods, such as in vitro methods of administering a compound or composition to cells for screening purposes and/or for conducting quality control assays.

In one aspect, provided is a method of treating a fibrotic disease in an individual in need thereof comprising administering to the individual a therapeutically effective amount of a compound of formula (I), or any variation thereof, e.g., a compound of formula (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a compound selected from the compounds depicted in Table 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof. In one aspect, the individual is a human. The individual, such as a human, may be in need of treatment, such as a human who has or is suspected of having a fibrotic disease. In one embodiment, a variation of the compounds includes any stereoisomer thereof.

In a further aspect, provided is a method of treating a fibrotic disease in an individual in need thereof comprising administering to the individual a therapeutically effective amount of a compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof. In one aspect, the individual is a human. The individual, such as a human, may be in need of treatment, such as a human who has or is suspected of having a fibrotic disease. In one embodiment, a variation of the compounds includes any stereoisomer thereof.

In another aspect, provided is a method of delaying the onset and/or development of a fibrotic disease in an individual (such as a human) who is at risk for developing a fibrotic disease. It is appreciated that delayed development may encompass prevention in the event the individual does not develop the fibrotic disease. An individual at risk of developing a fibrotic disease in one aspect has or is suspected of having one or more risk factors for developing a fibrotic disease. Risk factors for fibrotic disease may include an individual's age (e.g., middle-age or older adults), the presence of inflammation, having one or more genetic component associated with development of a fibrotic disease, medical history such as treatment with a drug or procedure believed to be associated with an enhanced susceptibility to fibrosis (e.g., radiology) or a medical condition believed to be associated with fibrosis, a history of smoking, the presence of occupational and/or environmental factors such as exposure to pollutants associated with development of a fibrotic disease. In some embodiments, the individual at risk for developing a fibrotic disease is an individual who has or is suspected of having NAFLD, NASH, CKD, scleroderma, Crohn's Disease, NSIP, PSC, PBC, or is an individual who has had or is suspected of having had a myocardial infarction.

In some embodiments, the fibrotic disease is fibrosis of a tissue such as the lung (pulmonary fibrosis), the liver, the skin, the heart (cardiac fibrosis), the kidney (renal fibrosis), or the gastrointestinal tract (gastrointestinal fibrosis).

In some embodiments, the fibrotic disease is pulmonary fibrosis (such as IPF), liver fibrosis, skin fibrosis, scleroderma, cardiac fibrosis, renal fibrosis, gastrointestinal fibrosis, primary sclerosing cholangitis, or biliary fibrosis (such as PBC).

In some embodiments, the fibrotic disease is a pulmonary fibrosis, e.g., idiopathic pulmonary fibrosis (IPF), interstitial lung disease, systemic sclerosis-associated interstitial lung disease, or radiation-induced pulmonary fibrosis. In some embodiments, the individual at risk for developing a fibrotic disease is an individual who has or is suspected of having a history of viral lung infections.

In some embodiments, the fibrotic disease is a primary sclerosing cholangitis, or biliary fibrosis.

In some embodiments, the fibrotic disease is fibrotic nonspecific interstitial pneumonia (NSIP).

In some embodiments, the fibrotic disease is a liver fibrosis, e.g., infectious liver fibrosis (from pathogens such as HCV, HBV or parasites such as schistosomiasis), NASH, alcoholic liver disease induced fibrosis, alcoholic steatosis induced liver fibrosis, nonalcoholic fatty liver disease, and cirrhosis.

In some embodiments, the fibrotic disease is biliary tract fibrosis.

In some embodiments, the fibrotic disease is renal fibrosis, e.g., diabetic kidney disease, diabetic nephrosclerosis, hypertensive nephrosclerosis, diabetic nephropathy, focal segmental glomerulosclerosis (“FSGS”), Alport syndrome, chronic kidney disease, and acute kidney injury from contrast induced nephropathy.

In some embodiments, the fibrotic disease is systemic and local sclerosis or scleroderma, keloids and hypertrophic scars, or post surgical adhesions.

In some embodiments, the fibrotic disease is atherosclerosis or restenosis.

In some embodiments, the fibrotic disease is a gastrointestinal fibrosis, e.g., Crohn's disease.

In some embodiments, the fibrotic disease is cardiac fibrosis, e.g., post myocardial infarction induced fibrosis and inherited cardiomyopathy.

In one aspect, provided is a compound of formula (I), or any variation thereof, e.g., a compound of formula (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a compound selected from the compounds depicted in Table 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, for use in the treatment of a fibrotic disease.

Also provided is use of a compound of formula (I), or any variation thereof, e.g., a compound of formula (II), a compound selected from the compounds depicted in Table 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for the treatment of a fibrotic disease.

In another aspect, provided is a method of inhibiting αvβ6 integrin in an individual comprising administering a compound of formula (I), or any variation thereof, e.g., a compound of formula (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a stereoisomer thereof, or a compound selected from the compounds depicted in Table 1, or a pharmaceutically acceptable salt thereof.

Also provided is a method of inhibiting TGFβ activation in a cell comprising administering to the cell a compound of formula (I), or any variation thereof, e.g., a compound of formula (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a compound selected from the compounds depicted in Table 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

Also provided is a method of inhibiting αvβ6 integrin in an individual in need thereof, comprising administering to the individual a compound of formula (I), or any variation thereof, e.g., a compound of formula (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a compound selected from the compounds depicted in Table 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof. In one such method, the compound is a selective αvβ6 integrin inhibitor. In another such method, the compound does not inhibit substantially α4β1, αvβ8 and/or α2β3 integrin. In yet another such method, the compound inhibits αvβ6 integrin but does not inhibit substantially α4β1 integrin. In still another such method, the compound inhibits αvβ6 integrin but does not inhibit substantially αvβ8 integrin. In a further such method, the compound inhibits αvβ6 integrin but does not inhibit substantially α2β3 integrin. In one embodiment is provided a method of inhibiting αvβ6 integrin and one or more of αvβ1, αvβ3, αvβ5, α2β1, α3β1, α6β1 integrin, α7β1 and α11β1 in an individual in need thereof. In another embodiment is provided a method of inhibiting αvβ6 integrin and αvβ1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin, αvβ3 integrin and αvβ5 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin and α2β1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin, α2β1 integrin and α3β1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin and α6β1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin and α7β1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin and α11β1 integrin. In all such embodiments, in one aspect the method of inhibition is for an individual in need thereof, such as an individual who has or is suspected of having a fibrotic disease, and wherein the method comprises administering to the individual a compound of formula (I), or any variation thereof, e.g., a compound of formula (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a compound selected from the compounds depicted in Table 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

Also provided is a method of modulating at least one integrin in a subject, the at least one integrin comprising an av subunit, the method comprising administering to the subject an effective amount of the compound of formula (I), or any variation thereof, e.g., a compound of formula (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a stereoisomer thereof, or a compound selected from the compounds depicted in Table 1, or a pharmaceutically acceptable salt thereof. In another aspect, the modulating comprising inhibiting the at least one integrin in the subject. In another aspect, the at least one integrin comprising at least one of αvβ₁ integrin and αvβ6 integrin. In another aspect, the subject has or is at risk of a fibrotic disease selected from the group consisting of: idiopathic pulmonary fibrosis (IPF), interstitial lung disease, radiation-induced pulmonary fibrosis, nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), alcoholic liver disease induced fibrosis, Alport syndrome, primary sclerosing cholangitis (PSC), primary biliary cholangitis, biliary atresia, systemic sclerosis associated interstitial lung disease, scleroderma, diabetic nephropathy, diabetic kidney disease, focal segmental glomerulosclerosis, chronic kidney disease, and Crohn's Disease; and the method comprises inhibiting one or both of αvβ₁ integrin and αvβ₆ integrin in the subject, thereby treating the fibrotic disease in the subject. In another aspect, the subject being in need of treatment for NASH, the effective amount administered to the subject being effective to inhibit at least αvβ₁ integrin, thereby treating the subject for NASH. In another aspect, the subject being in need of treatment for IPF, the effective amount administered to the subject being effective to inhibit at least αvβ₆ integrin, thereby treating the subject for IPF. In another aspect, the subject being in need of treatment for PSC, the effective amount administered to the subject being effective to inhibit at least one of αvβ₁ integrin and αvβ₆ integrin, thereby treating the subject for PSC.

Also provided is a method of modulating TGFβ activation in a cell, comprising contacting the cell with the compound of formula (I), or any variation thereof, e.g., a compound of formula (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a stereoisomer thereof, or a compound selected from the compounds depicted in Table 1, or a pharmaceutically acceptable salt thereof. In another aspect, the modulating comprising inhibiting TGFβ activation in the cell. In another aspect, the TGFβ activation being mediated in the cell by at least one of αvβ₁ integrin and αvβ₆ integrin.

Also provided is a method of treating a subject in need thereof, comprising: administering to the subject a therapeutically effective amount of the compound of formula (I), or any variation thereof, e.g., a compound of formula (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), or (Vb-2), a stereoisomer thereof, or a compound selected from the compounds depicted in Table 1, or a pharmaceutically acceptable salt thereof, wherein the subject has at least one tissue in need of therapy and the tissue has at least one elevated level of: TGFβ activation and/or expression; αvβ₁ integrin activity and/or expression; or αvβ₆ integrin activity and/or expression; wherein the at least one elevated level is elevated compared to a healthy state of the tissue. In some aspects, the method selectively inhibits αvβ₁ integrin compared to αvβ6 integrin in the subject. In some aspects, the method selectively inhibits αvβ6 integrin compared to αvβ₁ integrin in the subject. In some aspects, the method inhibits both of αvβ₁ integrin and αvβ6 integrin in the subject. In some aspects, the method selectively inhibits both αvβ₁ integrin and αvβ6 integrin compared to at least one other αv-containing integrin in the subject. In some aspects, the αvβ₁ integrin is inhibited in one or more fibroblasts in the subject. In some aspects, the αvβ6 integrin is inhibited in one or more epithelial cells in the subject. In some aspects, the at least one tissue in the subject comprises one or more of: lung tissue, liver tissue, skin tissue, cardiac tissue, kidney tissue, gastrointestinal tissue, gall bladder tissue, and bile duct tissue.

In one aspect, provided is a compound of formula (I), or any variation thereof, e.g., a compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, for use in the treatment of a fibrotic disease.

Also provided is use of a compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for the treatment of a fibrotic disease.

In another aspect, provided is a method of inhibiting αvβ6 integrin in an individual comprising administering a compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

Also provided is a method of inhibiting TGFβ activation in a cell comprising administering to the cell a compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

Also provided is a method of inhibiting αvβ6 integrin in an individual in need thereof, comprising administering to the individual a compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-1a), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof. In one such method, the compound is a selective αvβ6 integrin inhibitor. In another such method, the compound does not inhibit substantially α4β1, αvβ8 and/or α2β3 integrin. In yet another such method, the compound inhibits αvβ6 integrin but does not inhibit substantially α4β1 integrin. In still another such method, the compound inhibits αvβ6 integrin but does not inhibit substantially αvβ8 integrin. In a further such method, the compound inhibits αvβ6 integrin but does not inhibit substantially α2β3 integrin. In one embodiment is provided a method of inhibiting αvβ6 integrin and one or more of αvβ1, αvβ3, αvβ5, α2β1, α3β1, α6β1 integrin, α7β1 and α11β1 in an individual in need thereof. In another embodiment is provided a method of inhibiting αvβ6 integrin and αvβ1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin, αvβ3 integrin and αvβ5 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin and α2β1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin, α2β1 integrin and α3β1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin and α6β1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin and α7β1 integrin. In another embodiment is provided a method of inhibiting αvβ6 integrin and α11β1 integrin. In all such embodiments, in one aspect the method of inhibition is for an individual in need thereof, such as an individual who has or is suspected of having a fibrotic disease, and wherein the method comprises administering to the individual a compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof.

Also provided is a method of modulating at least one integrin in a subject, the at least one integrin comprising an av subunit, the method comprising administering to the subject an effective amount of the compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-ld-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof. In another aspect, the modulating comprising inhibiting the at least one integrin in the subject. In another aspect, the at least one integrin comprising at least one of αvβ₁ integrin and αvβ₆ integrin. In another aspect, the subject has or is at risk of a fibrotic disease selected from the group consisting of: idiopathic pulmonary fibrosis (IPF), interstitial lung disease, radiation-induced pulmonary fibrosis, nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), alcoholic liver disease induced fibrosis, Alport syndrome, primary sclerosing cholangitis (PSC), primary biliary cholangitis, biliary atresia, systemic sclerosis associated interstitial lung disease, scleroderma, diabetic nephropathy, diabetic kidney disease, focal segmental glomerulosclerosis, chronic kidney disease, and Crohn's Disease; and the method comprises inhibiting one or both of αvβ₁ integrin and αvβ₆ integrin in the subject, thereby treating the fibrotic disease in the subject. In another aspect, the subject being in need of treatment for NASH, the effective amount administered to the subject being effective to inhibit at least αvβ₁ integrin, thereby treating the subject for NASH. In another aspect, the subject being in need of treatment for IPF, the effective amount administered to the subject being effective to inhibit at least αvβ₆ integrin, thereby treating the subject for IPF. In another aspect, the subject being in need of treatment for PSC, the effective amount administered to the subject being effective to inhibit at least one of αvβ₁ integrin and αvβ₆ integrin, thereby treating the subject for PSC.

Also provided is a method of modulating TGFβ activation in a cell, comprising contacting the cell with the compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof. In another aspect, the modulating comprising inhibiting TGFβ activation in the cell. In another aspect, the TGFβ activation being mediated in the cell by at least one of αvβ₁ integrin and αvβ₆ integrin.

Also provided is a method of treating a subject in need thereof, comprising: administering to the subject a therapeutically effective amount of the compound of formula (I), or any variation thereof, e.g., a compound of formulae (I), (IIa), (IIb), (IIIa), (IIIb), (IVa), (IVb), (Va), (Va-1), (Va-2), (Vb), (Vb-1), (Vb-2), (II-A-1), (II-A-2), (II-A-2i), (II-A-2ii), (II-A-1a-1), (II-A-1a-2), (II-A-1a-3), (II-A-1b-1), (II-A-1b-2), (II-A-1c-1), (II-A-1c-2), (II-A-1d-1), (II-A-1d-2), (II-A-1d-3), (II-A-2a-1), (II-A-2a-2), (II-A-2a-3), (II-A-2a-4), (II-A-2b-1), (II-A-2b-2), (II-A-2c-1), (II-A-2c-2), (II-A-2c-3), (II-A-2c-4), (II-A-2d-1), (II-A-2d-2), (II-A-2d-3), (II-A-2d-4), (II-A-2d-5), (II-A-2d-6), (II-A-2e-1), (II-A-2e-2), (II-A-2e-3), (II-A-2e-4), (II-A-2e-5), (II-A-2e-6), (II-A-2e-7), (II-A-2e-8), (II-A-2f-1), (II-A-2f-2), (II-A-2f-3), (II-A-2f-4), (II-A-2f-5), (II-A-2f-6), (II-A-2f-7), (II-A-2f-8), (II-A-2f-9), (II-A-2f-10), (II-B-1), (II-B-2), (II-B-3), (II-B-la), (II-B-2a), (II-B-2b), (II-B-3a), or (II-B-3b), a compound selected from the compounds depicted in Table 1 or Table 2, or any one of compounds 1-329, or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, wherein the subject has at least one tissue in need of therapy and the tissue has at least one elevated level of: TGFβ activation and/or expression; αvβ₁ integrin activity and/or expression; or αvβ₆ integrin activity and/or expression; wherein the at least one elevated level is elevated compared to a healthy state of the tissue. In some aspects, the method selectively inhibits αvβ₁ integrin compared to αvβ₆ integrin in the subject. In some aspects, the method selectively inhibits αvβ₆ integrin compared to αvβ₁ integrin in the subject. In some aspects, the method inhibits both of αvβ₁ integrin and αvβ₆ integrin in the subject. In some aspects, the method selectively inhibits both αvβ₁ integrin and αvβ₆ integrin compared to at least one other αv-containing integrin in the subject. In some aspects, the αvβ₁ integrin is inhibited in one or more fibroblasts in the subject. In some aspects, the αvβ₆ integrin is inhibited in one or more epithelial cells in the subject. In some aspects, the at least one tissue in the subject comprises one or more of: lung tissue, liver tissue, skin tissue, cardiac tissue, kidney tissue, gastrointestinal tissue, gall bladder tissue, and bile duct tissue.

In any of the described methods, in one aspect the individual is a human, such as a human in need of the method. The individual may be a human who has been diagnosed with or is suspected of having a fibrotic disease. The individual may be a human who does not have detectable disease but who has one or more risk factors for developing a fibrotic disease.

Kits

The invention further provides kits for carrying out the methods of the invention, which comprises one or more compounds described herein, or a salt thereof, or a pharmacological composition comprising a compound described herein. The kits may employ any of the compounds disclosed herein. In one variation, the kit employs a compound described herein or a pharmaceutically acceptable salt thereof. The kits may be used for any one or more of the uses described herein, and, accordingly, may contain instructions for use in the treatment of a fibrotic disease.

Kits generally comprise suitable packaging. The kits may comprise one or more containers comprising any compound described herein. Each component (if there is more than one component) can be packaged in separate containers or some components can be combined in one container where cross-reactivity and shelf life permit. One or more components of a kit may be sterile and/or may be contained within sterile packaging.

The kits may be in unit dosage forms, bulk packages (e.g., multi-dose packages) or sub-unit doses. For example, kits may be provided that contain sufficient dosages of a compound as disclosed herein (e.g., a therapeutically effective amount) and/or a second pharmaceutically active compound useful for a disease detailed herein (e.g., fibrosis) to provide effective treatment of an individual for an extended period, such as any of a week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, 8 weeks, 3 months, 4 months, 5 months, 7 months, 8 months, 9 months, or more. Kits may also include multiple unit doses of the compounds and instructions for use and be packaged in quantities sufficient for storage and use in pharmacies (e.g., hospital pharmacies and compounding pharmacies).

The kits may optionally include a set of instructions, generally written instructions, although electronic storage media (e.g., magnetic diskette or optical disk) containing instructions are also acceptable, relating to the use of component(s) of the methods of the present invention. The instructions included with the kit generally include information as to the components and their administration to an individual.

General Procedures

Compounds provided herein may be prepared according to General Schemes, as exemplified by the General Procedures and Examples.

When a specific stereoisomer, or an unspecified stereoisomer, or a mixture of stereoisomers is shown in the following general procedures, it is understood that similar chemical transformations can be performed on other specific stereoisomers, or an unspecified stereoisomer, or mixtures thereof. For example, a hydrolysis reaction of an L-homoserinate ester to an L-homoserine (i.e., free acid) can also be performed on a D-homoserinate ester to prepare a D-homoserine, or on a mixture of an L-homoserinate ester and a D-homoserinate ester to prepare a mixture of an L-homoserine and a D-homoserine. As another example, reactions of functional groups on a compound containing a trans-cyclobutyl group can also be performed on a compound containing a cis-cyclobutyl group, or on a mixture of a compound containing a cis-cyclobutyl group and a compound containing a trans-cyclobutyl group. As another example, reactions of functional groups on a compound containing a cycloalkyl Y group can also be performed on a compound lacking a Y group (i.e., where the linker is -L₁-O-L₂-L₃- as defined in Formula (I)), or on a mixture of a compound containing a cycloalkyl group and a compound lacking a Y group.

Some of the following general procedures use specific compounds to illustrate a general reaction (e.g., deprotection of a compound having a Boc-protected amine to a compound having a deprotected amine using acid). The general reaction can be carried out on other specific compounds having the same functional group (e.g., a different compound having a protected amine where the Boc-protecting group can be removed using acid in the same manner) as long as such other specific compounds do not contain additional functional groups affected by the general reaction (i.e., such other specific compounds do not contain acid-sensitive functional groups), or if the effect of the general reaction on those additional functional groups is desired (e.g., such other specific compounds have another group that is affected by acid, and the effect of the acid on that other group is a desirable reaction).

Where specific reagents or solvents are specified for reactions in the general procedures, the skilled artisan will recognize that other reagents or solvents can be substituted as desired. For example, acetylation is performed in the general examples with acetic anhydride, but an active ester of acetic acid can also be used. As another example, where hydrochloric acid is used to remove a Boc group, trifluoroacetic acid can be used instead. As another example, where HATU is used as a coupling reagent, BOP or PyBOP can be used instead.

General Procedure A

methyl (1r,3r)-3-((tert-butyldimethylsilyl)oxy)cyclobutane-1-carboxylate

To a solution of methyl (1r,3r)-3-hydroxycyclobutane-1-carboxylate (5.0 g, 38.42 mmol) in CH₂Cl₂ (100 mL) was added imidazole (3.92 g, 57.63 mmol) then TBSCl (6.95 g, 46.10 mmol) at room temperature and the resulting heterogeneous mixture was vigorously stirred for 30 minutes. The reaction mixture was diluted with sat. NaHCO₃ and water and stirred for 5 minutes. The layers were separated and the organic layer was washed with water (50 mL), dried over MgSO₄, filtered and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give methyl (1r,3r)-3-((tert-butyldimethylsilyl)oxy)cyclobutane-1-carboxylate.

((1r,3r)-3-((tert-butyldimethylsilyl)oxy)cyclobutyl)methanol

To a solution of methyl (1r,3r)-3-((tert-butyldimethylsilyl)oxy)cyclobutane-1-carboxylate (9.19 g, 37.60 mmol) at −78° C. in THF (92 mL) was added Dibal-H (1.0 M in heptane, 94 mL, 94.00 mmol) dropwise and the resulting solution was allowed to stir for 1 hr at −78° C. The mixture was then warmed to 0° C. and then to this was slowly added EtOAc (100 mL) followed by a saturated aqueous solution of sodium potassium tartrate (250 mL) and water (100 mL) and the resulting mixture was then allowed to warm to room temperature and stirred vigorously for 4 hrs. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give ((1r,3r)-3-((tert-butyldimethylsilyl)oxy)cyclobutyl)methanol.

tert-butyl((1r,3r)-3-(iodomethyl)cyclobutoxy)dimethylsilane

To a solution of PPh₃ (13.09 g, 49.91 mmol) and imidazole (4.53 g, 66.54 mmol) in CH₂Cl₂ (78 mL) at 0° C. was slowly added 12 (12.24 g, 48.24 mmol) and the mixture was stirred an additional 30 minutes and then allowed to warm to room temperature. A solution of ((1r,3r)-3-((tert-butyldimethylsilyl)oxy)cyclobutyl)methanol (7.2 g, 33.27 mmol) in CH₂Cl₂ (20 mL) was then added to the reaction mixture and stirred for 6 hrs at room temperature. The reaction mixture was then diluted with sat. NaHCO₃ and stirred for 15 minutes. The layers were separated and the organic layer was washed with H₂O, dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give tert-butyl((1r,3r)-3-(iodomethyl)cyclobutoxy)dimethylsilane.

4-((1r,3s)-3-hydroxycyclobutyl)butan-2-one

To a solution of acetone dimethylhydrazone (8.33 g, 83.13 mmol) at −78° C. in THF (83 mL) was slowly added n-BuLi (2.5 M in hexanes, 32.59 mL, 81.46 mmol) causing a pale yellow suspension to occur. Upon completion of the addition, the resulting suspension was stirred an additional 15 minutes, at which time, a solution of tert-butyl((1r,3r)-3-(iodomethyl)cyclobutoxy)dimethylsilane (10.85 g, 33.25 mmol) in THF (20 mL) was slowly added dropwise. The resulting mixture was warmed to 0° C. and stirred for 30 minutes and then carefully quenched with aq 1M HCl (250 mL) and acetone (50 mL). The resulting mixture was allowed to stir at room temperature overnight and then was extracted with EtOAc. The combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give 4-((1r,3 s)-3-hydroxycyclobutyl)butan-2-one.

(1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutan-1-ol

A sealed tube containing 4-((1r,3s)-3-hydroxycyclobutyl)butan-2-one (2.46 g, 17.30 mmol) was charged with L-proline (996 mg, 8.65 mmol) and 2-aminonicotinaldehyde (2.53 g, 20.76 mmol) and then diluted with 200 proof EtOH (50 mL) and then sealed and placed in an aluminum block and heated to 95° C. overnight. The reaction mixture was allowed to cool to room temperature and then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give (1 s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutan-1-ol.

2-(2-((1r,3s)-3-(allyloxy)cyclobutyl)ethyl)-1,8-naphthyridine

To a solution of (1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutan-1-ol (3.36 g, 14.72 mmol) in 2:1 THF/DMF (34 mL) at room temperature was slowly added NaH (60% dispersion in mineral oil, 883 mg, 22.08 mmol) and the resulting mixture was stirred for 30 minutes, at which time, allyl bromide (1.91 mL, 22.08 mmol) was added and the resulting mixture was warmed to 50° C. for 1 hr. The reaction mixture was cooled to room temperature and then carefully diluted with sat NaHCO₃ and H₂O. The resulting mixture was extracted with 4:1 DCM/iPrOH and the combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give 2-(2-((1r,3s)-3-(allyloxy)cyclobutyl)ethyl)-1,8-naphthyridine.

2-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)acetaldehyde

To a solution of 2-(2-((1r,3 s)-3-(allyloxy)cyclobutyl)ethyl)-1,8-naphthyridine (1.38 g, 5.14 mmol) in 3:1 Dioxane/H₂O (14 mL) was added 2,6-lutidine (1.2 mL, 10.28 mmol), NaIO4 (4.40g, 20.56 mmol), then OsO₄ (2.5 wt % in t-BuOH, 1.05 mL, 0.10 mmol) and the resulting mixture was allowed to stir at room temperature for 4 hrs. The reaction mixture was diluted with sat NaHCO₃ and H₂O and stirred for 15 minutes and then filtered through a coarse fritted funnel and the filter cake was rinsed with 4:1 DCM/iPrOH. The layers were separated and the aqueous layer was extracted with 4:1 DCM/iPrOH and the combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo to give 2-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)acetaldehyde.

methyl 4-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)but-2-enoate

To a solution of 2-((1 s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)acetaldehyde in CH₂Cl₂ (14 mL) and to this was added methyl 2-((tert-butoxycarbonyl)amino)-2-(dimethoxyphosphoryl)acetate (2.29 g, 7.71 mmol) then DBU (1.16 mL, 7.71 mmol) and the resulting mixture was allowed to stir at room temperature for 30 minutes and then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give methyl 4-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)but-2-enoate.

methyl N-(tert-butoxycarbonyl)-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

A flask containing methyl 4-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)but-2-enoate (2.27 g, 5.14 mmol) was charged with Pd(OH)₂/C (20 wt % on carbon, 454 mg) and then diluted with MeOH (23 mL). The flask was then evacuated and backfilled with H₂ for 3 cycles and then stirred under an H₂ atmosphere overnight. The reaction mixture was then filtered through a pad of Celite and then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give methyl N-(tert-butoxycarbonyl)-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate.

After the synthesis of the racemic material as shown in the previous step, a chiral separation can be performed to afford two single enantiomers using chiral SFC with the following method: Chiralpak AY-H, 250*25 mm i.d. 10u; Mobile phase: A for CO2 and B for EtOH (0.1% NH3H2O); Gradient: B %=45%; Flow rate: 80 g/min; Wavelength: 220 nm; Column temperature: 40° C.; System back pressure: 100 bar.

General Procedure B

methyl (1s,3s)-3-((tert-butyldimethylsilyl)oxy)cyclobutane-1-carboxylate

To a solution of methyl (1s,3s)-3-hydroxycyclobutane-1-carboxylate (5.0 g, 38.16 mmol) in CH₂Cl₂ (100 mL) was added imidazole (3.92 g, 57.63 mmol) then TBSCl (6.95 g, 49.61 mmol) at room temperature and the resulting heterogeneous mixture was vigorously stirred for 30 minutes. The reaction mixture was diluted with sat. NaHCO₃(50 mL) and water (50 mL) and stirred for 5 minutes. The layers were separated and the organic layer was washed with water (50 mL), dried over MgSO₄, filtered and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give methyl (1s,3s)-3-((tert-butyldimethylsilyl)oxy)cyclobutane-1-carboxylate.

((1s,3s)-3-((tert-butyldimethylsilyl)oxy)cyclobutyl)methanol

To a solution of methyl (1s,3s)-3-((tert-butyldimethylsilyl)oxy)cyclobutane-1-carboxylate (9.20 g, 37.76 mmol) at −78° C. in THF (92 mL) was added Dibal-H (1.0 M in heptane, 113 mL, 113.00 mmol) dropwise and the resulting solution was allowed to stir for 1 hr at −78° C. The mixture was then warmed to 0° C. and then to this was slowly added EtOAc (100 mL) followed by a saturated aqueous solution of sodium potassium tartrate (250 mL) and water (100 mL) and the resulting mixture was then allowed to warm to room temperature and stirred vigorously for 4 hrs. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give ((1s,3s)-3-((tert-butyldimethylsilyl)oxy)cyclobutyl)methanol.

tert-butyl((1s,3s)-3-(iodomethyl)cyclobutoxy)dimethylsilane

To a solution of PPh₃ (12.80 g, 48.79 mmol) and imidazole (4.43 g, 65.05 mmol) in CH₂Cl₂ (72 mL) at 0° C. was slowly added 12 (11.97 g, 47.16 mmol) and the mixture was stirred an additional 30 minutes and then allowed to warm to room temperature. A solution of ((1s,3s)-3-((tert-butyldimethylsilyl)oxy)cyclobutyl)methanol (7.04 g, 32.53 mmol) in CH₂Cl₂ (20 mL) was then added to the reaction mixture and stirred for 6 hrs at room temperature. The reaction mixture was then diluted with sat. NaHCO₃ and stirred for 15 minutes. The layers were separated and the organic layer was washed with H₂O, dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give tert-butyl((1s,3 s)-3-(iodomethyl)cyclobutoxy)dimethylsilane.

4-((1s,3r)-3-hydroxycyclobutyl)butan-2-one

To a solution of acetone dimethylhydrazone (8.15 g, 81.39 mmol) at −78° C. in THF (82 mL) was slowly added n-BuLi (2.5 M in hexanes, 31.25 mL, 78.13 mmol) causing a pale yellow suspension to occur. Upon completion of the addition, the resulting suspension was stirred an additional 15 minutes, at which time, a solution of tert-butyl((1 s,3 s)-3-(iodomethyl)cyclobutoxy)dimethylsilane (10.62 g, 32.55 mmol) in THF (20 mL) was slowly added dropwise. The resulting mixture was warmed to 0° C. and stirred for 30 minutes and then carefully quenched with aq 1M HCl (250 mL) and acetone (50 mL). The resulting mixture was allowed to stir at room temperature overnight and then was extracted with EtOAc. The combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give 4-((1s,3r)-3-hydroxycyclobutyl)butan-2-one.

(1r,3s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutan-1-ol

A sealed tube containing 4-((1s,3r)-3-hydroxycyclobutyl)butan-2-one (2.72 g, 19.18 mmol) was charged with L-proline (1.10 g, 9.59 mmol) and 2-aminonicotinaldehyde (3.51 g, 28.77 mmol) and then diluted with 200 proof EtOH (50 mL) and then sealed and placed in an aluminum block and heated to 95° C. overnight. The reaction mixture was allowed to cool to room temperature and then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give (1r,3 s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutan-1-ol.

2-(2-((1s,3r)-3-(allyloxy)cyclobutyl)ethyl)-1,8-naphthyridine

To a solution of (1r,3s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutan-1-ol (3.72 g, 16.30 mmol) in 2:1 THF/DMF (37 mL) at room temperature was slowly added NaH (60% dispersion in mineral oil, 847 mg, 21.18 mmol) and the resulting mixture was stirred for 30 minutes, at which time, allyl bromide (1.83 mL, 21.18 mmol) was added and the resulting mixture was warmed to 50° C. for 1 hr. The reaction mixture was cooled to room temperature and then carefully diluted with sat NaHCO₃ and H₂O. The resulting mixture was extracted with 4:1 DCM/iPrOH and the combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give 2-(2-((1s,3r)-3-(allyloxy)cyclobutyl)ethyl)-1,8-naphthyridine.

2-((1r,3s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)acetaldehyde

To a solution of 2-(2-((1 s,3r)-3-(allyloxy)cyclobutyl)ethyl)-1,8-naphthyridine (946 mg, 3.53 mmol) in 3:1 Dioxane/H₂O (10 mL) was added 2,6-lutidine (0.82 mL, 7.05 mmol), NaIO4 (3.02 g, 14.10 mmol), then OsO₄ (2.5 wt % in t-BuOH, 0.88 mL, 0.07 mmol) and the resulting mixture was allowed to stir at room temperature for 4 hrs. The reaction mixture was diluted with sat NaHCO₃ and H₂O and stirred for 15 minutes and then filtered through a coarse fritted funnel and the filter cake was rinsed with 4:1 DCM/iPrOH. The layers were separated and the aqueous layer was extracted with 4:1 DCM/iPrOH and the combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo to give 2-((1r,3s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)acetaldehyde.

methyl 4-((1r,3s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)but-2-enoate

To a solution of 2-((1r, 3 s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)acetaldehyde (953 mg, 3.53 mmol) in CH₂Cl₂ (10 mL) and to this was added methyl 2-((tert-butoxycarbonyl)amino)-2-(dimethoxyphosphoryl)acetate (1.57 g, 5.29 mmol) then DBU (0.64 mL, 4.23 mmol) and the resulting mixture was allowed to stir at room temperature for 30 minutes and then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give methyl 4-((1r,3s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)but-2-enoate.

methyl N-(tert-butoxycarbonyl)-O-((1r,3s)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

A flask containing methyl 4-((1r,3 s)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)but-2-enoate (846 mg, 1.92 mmol) was charged with Pd(OH)₂/C (20 wt % on carbon, 169 mg) and then diluted with MeOH (9 mL). The flask was then evacuated and backfilled with H₂ for 3 cycles and then stirred under an H₂ atmosphere overnight. The reaction mixture was then filtered through a pad of Celite and then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give methyl N-(tert-butoxycarbonyl)-O-((1r,3s)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate.

After the synthesis of the racemic material as shown in the previous step, a chiral separation can be performed to afford two single enantiomers using chiral SFC with the following method: Chiralpak AY-H 250*30 mm i.d. 5u; mobile phase: A for CO2 and B for EtOH (0.1% NH3H₂O); gradient: B %=50%; flow rate: 80g/min; wavelength: 220 nm; column temperature: 40° C.; system back pressure: 100 bar.

General Procedure C

4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butan-1-ol

To a suspension of 4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butanoic acid hydrochloride (1.23 g, 4.79 mmol, 1.0 equiv) in THF was added LiAlH₄ (1.0M in THF, 10.6 mL, 10.6 mmol) dropwise and the resulting mixture was refluxed overnight. The mixture was then cooled in an ice bath and to this was slowly added H₂O (400 μL), then aqueous 1.0 M NaOH (400 μL), then H₂O (400 μL) again and stirred for 15 minutes and then a large excess of MgSO₄ was added and stirred for an additional 30 minutes. The resulting organic mixture was filtered and then concentrated in vacuo to provide 4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butan-1-ol.

7-(4-(allyloxy)butyl)-1,2,3,4-tetrahydro-1,8-naphthyridine

To a stirring suspension of NaH (60 wt % dispersion in mineral oil, 238 mg, 5.96 mmol) in THF (8.2 mL) at 0° C. was added a solution of 4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butan-1-ol (820 mg, 3.98 mmol) in THF (4.1 mL) dropwise. Upon completion of the addition, the ice bath was removed and the resulting mixture was stirred at room temperature for 30 minutes, at which time, allyl bromide (400 μL, 4.62 mmol) was added dropwise. The suspension was stirred for an additional 6 hrs at room temperature and then carefully diluted with H₂O and EtOAc. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by silica gel chromatography to provide 7-(4-(allyloxy)butyl)-1,2,3,4-tetrahydro-1,8-naphthyridine.

2-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy)acetaldehyde

To a solution of 7-(4-(allyloxy)butyl)-1,2,3,4-tetrahydro-1,8-naphthyridine (582 mg, 2.36 mmol) in 3:1 THF/H₂O (6 mL) at room temperature was added NaIO₄ (2.02 g, 9.44 mmol) followed by OsO₄ (2.5 wt % in t-BuOH, 480 μL, 0.05 mmol). The resulting suspension was stirred at room temperature for 5 hrs and then diluted with 1:1 sat. aq. NaHCO₃/sat. aq. Na₂S₂O₃ and EtOAc and then stirred for 1 hr at room temperature. The biphasic mixture was filtered through a small pad of Celite and then the layers were separated. The aqueous layer was extracted with EtOAc and the combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo to provide 2-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy)acetaldehyde that was used without further purification.

methyl 2-((tert-butoxycarbonyl)amino)-4-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy)but-2-enoate

To a solution of 2-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy)acetaldehyde (586 mg, 2.36 mmol) in CH₂Cl₂ (6 mL) at room temperature was added methyl 2-(((benzyloxy)carbonyl)amino)-2-(dimethoxyphosphoryl)acetate (860 mg, 2.60 mmol) followed by DBU (391 μL, 2.60 mmol) and stirred for 30 minutes at room temperature. The mixture was diluted with sat. aq. NH4Cl and stirred for 5 minutes at room temperature. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by silica gel chromatography to provide methyl 2-((tert-butoxycarbonyl)amino)-4-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy)but-2-enoate.

methyl N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserinate

A flask containing methyl 2-((tert-butoxycarbonyl)amino)-4-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy)but-2-enoate (497 mg, 1.10 mmol) and 20 wt % Pd(OH)₂ on carbon (100 mg) was diluted with MeOH (5 ml) and then evacuated and backfilled with H₂ for 3 cycles and then stirred under an H₂ atmosphere for 3 hrs. The resulting mixture was filtered through a pad of Celite and then concentrated in vacuo to give methyl N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserinate (352 mg) that was used without further purification.

After the synthesis of the racemic material as shown in the previous step, a chiral separation can be performed to afford two single enantiomers using chiral SFC with the following method: Chiralpak AY-H 250*30 mm i.d. 5u; mobile phase: A for CO2 and B for IPA (0.1% NH3H₂O); gradient: B %=40%; flow rate: 70 g/min; wavelength: 220 nm; column temperature: 40° C.; system back pressure: 100 bar.

General Procedure D

Methyl O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

To a solution of methyl N-(tert-butoxycarbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate (2.26 g, 5.05 mmol) in DCM (13 mL) was added 4 N HCl in 1,4-dioxane (10 mL, 40 mmol). The reaction was allowed to stir at rt overnight. LCMS then showed the consumption of starting material. The reaction was concentrated and used in the next step without further purification.

General Procedure E

Methyl N-(quinazolin-4-yl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

To a solution of methyl O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate (14 mg, 0.040 mmol) in IPA (2 mL) was added 4-chloroquinazoline (9.9 mg, 0.060 mmol) and DIPEA (0.035 mL, 0.20 mmol). The reaction was heated at 60 C for 18 h. The reaction mixture was then concentrated and used directly in the next step.

General Procedure E can be used in the coupling step of compound 14A, or a similar compounds, with compound 15A in General Scheme A, General Scheme B, General Scheme C, General Scheme D-2, General Scheme E-2, General Scheme F-2, General Scheme G-2, or General Scheme H.

General Procedure F

methyl N-(isopropoxycarbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

Methyl O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate (54 mg, 0.16 mmol) in CH₂Cl₂ (2.0 mL) was added DIPEA (60 mg, 0.47 mmol) was added isopropyl carbonochloridate (23 mg, 0.19 mmol) and the resulting mixture was stirred at room temperature overnight and then concentrated in vacuo. The crude product was used without further purification.

General Procedure F can be used in the coupling step of compound 14A, or a similar compounds, with compound 16A in General Scheme A, General Scheme B, General Scheme C, General Scheme D-2, General Scheme E-2, General Scheme F-2, General Scheme G-2, or General Scheme H.

General Procedure G

methyl N-(tert-butylcarbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

To a solution of methyl O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate (71 mg, 0.20 mmol) in DCM (2.4 mL) was added imidazole (15 mg, 0.22 mmol) and CDI (36 mg, 0.22 mmol). This mixture was allowed to stir at rt for 30 min before adding tert-butylamine (22 mg, 0.31 mmol). The reaction was stirred at rt for 18 h. LCMS indicated that methyl O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate remained, and imidazole (15 mg, 0.22 mmol), CDI (36 mg, 0.22 mmol), and tert-butylamine (22 mg, 0.31 mmol) were added. After 5 h, the reaction was concentrated in vacuo and the resulting crude residue was purified by normal phase silica gel chromatography to give methyl N-(tert-butylcarbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate.

General Procedure H

methyl N-(diethylcarbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

To a mixture of methyl O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate (57 mg, 0.16 mmol) in DCM (2.4 mL) at rt was added DIPEA (0.23 mL, 1.3 mmol) then diethylcarbamoyl chloride (0.10 mL, 0.82 mmol) and the resulting reaction mixture was stirred at rt overnight. The mixture was concentrated in vacuo and the resulting crude residue was purified by preparative reverse phase HPLC to give methyl N-(diethylcarbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate.

General Procedure H can be used in the coupling step of compound 14A, or a similar compounds, with compound 16A in General Scheme A, General Scheme B, General Scheme C, General Scheme D-2, General Scheme E-2, General Scheme F-2, General Scheme G-2, or General Scheme H.

General Procedure I

Methyl O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserinate

To a solution of methyl O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate (1.62 g, 4.68 mmol) in DMF (10 mL) was added DIPEA (5.7 mL, 32 mmol), HATU (2.0 g, 5.1 mmol), and 4-(trifluoromethyl)tetrahydro-2H-pyran-4-carboxylic acid (1.0 g, 5.1 mmol). The reaction was allowed to stir at rt for 18 h. LCMS showed product mass, and the reaction was concentrated, diluted with EtOAc and aqueous sat. sodium bicarbonate solution. The layers were separated, and the aqueous layer was extracted two times. Combined organic layers were dried over sodium sulfate, filtered, and concentrated to afford crude product, which was purified by silica gel chromatography to afford methyl O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserinate.

General Procedure I can be used in the coupling step of compound 14A, or a similar compounds, with compound 16A in General Scheme A, General Scheme B, General Scheme C, General Scheme D-2, General Scheme E-2, General Scheme F-2, General Scheme G-2, or General Scheme H.

General Procedure J

The following transformation:

wherein R is R^(2f) as defined for formula (I), or any applicable variations detailed herein, can be performed as exemplified below.

tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-3-methylazetidine-1-carboxylate

To a mixture of tert-butyl 3-hydroxy-3-methylazetidine-1-carboxylate (1.1 g, 5.8 mmol) and N,N-diisopropylethylamine (2.02 mL, 11.6 mmol) in acetonitrile (10 mL) was added disuccinimidyl carbonate (3.0 g, 11.6 mmol) and the resulting mixture was stirred at room temperature for 14 hours. The reaction mixture was diluted with water and extracted with EtOAc. The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to afford tert-butyl 3-((((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)carbonyl)oxy)-3-methylazetidine-1-carboxylate.

General Procedure J can be used to make the appropriate reagent for use in General Procedure K

General Procedure K

The following transformation:

wherein R^(2f) is as defined for formula (I), or any applicable variations detailed herein, can be performed as exemplified below.

tert-butyl 3-(((1-methoxy-1-oxo-4-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butan-2-yl)azetidine-1-carboxylate

To a solution of methyl O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate dihydrochloride (220.0 mg, 0.63 mmol) and N,N-diisopropylethylamine (0.4 mL, 2.5 mmol) in dichloromethane (2.0 mL) was added tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-3-methylazetidine-1-carboxylate (249.5 mg, 0.8 mmol) and the resulting mixture was stirred at room temperature for 1 hour. The reaction mixture was concentrated in vacuo and purified by normal phase silica gel column chromatography to afford tert-butyl 3-(((1-methoxy-1-oxo-4-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butan-2-yl)carbamoyl)oxy)-3-methylazetidine-1-carboxylate.

General Procedure K can be used in the coupling step of compound 14A, or a similar compounds, with compound 16A in General Scheme A, General Scheme B, General Scheme C, General Scheme D-2, General Scheme E-2, General Scheme F-2, General Scheme G-2, and General Scheme H.

General Procedure L

The following transformation:

wherein Z refers to that portion of the molecule which links the —(O)_(n)C(O)N(H)CH(COOCH₃)L¹- portion of the molecule with the remainder of the R² moiety, wherein n is 0 or 1, L¹ and R² are as defined for formula (I), or any applicable variations detailed herein, can be performed as exemplified below. In some variations, Z is an alkylene moiety and R is hydrogen. In some variations, Z is taken together with the adjacent “NR” group to form a heterocyclic ring.

methyl N-(((1-acetyl-3-methylazetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

To a solution of methyl N-(((3-methylazetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate bis(2,2,2-trifluoroacetate) (35.0 mg, 0.05 mmol) and N,N-diisopropylethylamine (52.9 μL, 0.304 mmol) in dichloromethane (2.0 mL) at 0° C. was added acetic anhydride (8.6 μL, 0.091 mmol). The reaction mixture was removed from the ice bath and allowed to warm to room temperature. After 20 minutes the reaction mixture was concentrated in vacuo and used without further purification.

General Procedure M

The following transformation:

wherein Z refers to that portion of the molecule which links the —(O)_(n)C(O)N(H)CH(COOCH₃)L¹- portion of the molecule with the remainder of the R² moiety, wherein n is 0 or 1, L¹ and R² are as defined for formula (I), or any applicable variations detailed herein, can be performed as exemplified below. In some variations, Z is an alkylene moiety and R is hydrogen. In some variations, Z is taken together with the adjacent “NR” group to form a heterocyclic ring.

methyl N-(((3-methyl-1-(methylsulfonyl)azetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate

To a solution of methyl N-(((3-methylazetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate bis(2,2,2-trifluoroacetate) (28.0 mg, 0.04 mmol) and N,N-Diisopropylethylamine (42.4 μL, 0.24 mmol) in dichloromethane (2.0 mL) at 0° C. was added methanesulfonyl chloride (5.6 μL, 0.073 mmol). The reaction mixture was removed from the ice bath and allowed to warm to room temperature. After 20 minutes the reaction mixture was concentrated in vacuo and used without further purification.

General Procedure N

N-(4-cyano-2,6-dimethylbenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

To a solution of methyl N-(4-cyano-2,6-dimethylbenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate (427 mg, 0.846 mmol) in THF/MeOH/H2O 3:1:1 was added LiOH (81.0 mg, 3.38 mmol). The reaction was allowed to stir at rt for 4 h. LCMS showed conversion to product, and the reaction mixture was diluted with water and purified by reverse phase preparative HPLC to afford N-(4-cyano-2,6-dimethylbenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine as a TFA salt.

General Procedure O Synthesis of tert-butyl 7-(4-oxobutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate

tert-butyl 7-(4-ethoxy-4-oxobutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate

To a solution of ethyl 4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butanoate (5.25g, 21.1 mmol) and di-tert-butyl dicarbonate (5.89 mL, 25.4 mmol in THF (70 mL) was added lithium bis(trimethylsilyl)amide (25.4 mL, 25.4 mmol) was added at 0° C. After 2 hr, the reaction was diluted with EtOAc (50 mL) and was quenched with sat NH4Cl (50 mL). After 30 min of stirring, the layers were separated and the organic layer was washed with brine (20 mL), dried over Na₂SO₄, and concentrated in vacuo. The resulting crude residue was purified by normal phase silica gel chromatography to give tert-butyl 7-(4-ethoxy-4-oxobutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate.

tert-butyl 7-(4-hydroxybutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate

To a solution of tert-butyl 7-(4-ethoxy-4-oxobutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate (6.81 g, 19.5 mmol) in THF (50 mL) was added LiBH₄ (1.0M in THF, 19.5 mL, 19.5 mmol) at rt. The mixture was stirred overnight and then quenched with sat. NH4Cl and diluted with EtOAc. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were washed with H₂O, dried over Na₂SO₄, filtered, and concentrated in vacuo. The resulting crude residue was purified by normal phase silica gel chromatography to give tert-butyl 7-(4-hydroxybutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate.

tert-butyl 7-(4-oxobutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate

A solution of oxalyl chloride (2.57 mL, 29.3 mmol) in CH₂Cl₂ (69 mL) was cooled to −78° C. for 5 minutes, at which time, dimethyl sulfoxide (4.2 mL, 58.6 mmol) was added and the mixture was stirred for 30 min. A solution of tert-butyl 7-(4-hydroxybutyl)-3,4-dihydro-2H-1,8-naphthyridine-1-carboxylate (6.9 g, 22.6 mmol) in CH₂Cl₂ (10.5 mL) was added and stirred at −78° C. for 1 hr. Triethylamine (10.5 mL, 75.1 mmol) was then added to the reaction mixture and stirred for 30 mins. The reaction was quenched with water and extracted with CH₂Cl₂. The organic layer was collected and dried over sodium sulfate. The organic layer was concentrate to give tert-butyl 7-(4-oxobutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate that was used without further purification.

General Procedure P Synthesis of 3-(thiazol-5-yl)benzoic Acid

methyl 3-(thiazol-5-yl)benzoate

A microwave vial was charged with (3-(methoxycarbonyl)phenyl)boronic acid (513 mg, 2.85 mmol), 5-bromothiazole (513 mg, 3.13 mmol), and Pd(PPh₃)₄ (132 mg, 0.11 mmol) and then diluted with dioxane (5 mL) and 2M aq. K₂CO₃ (4.25 mL). The mixture was degassed by bubbling N₂ through the solution while vigorously stirring at rt and then sealed and heated to 100° C. for 30 min. The reaction mixture was cooled to rt and diluted with EtOAc and H₂O. The layers were separated and the organic layer was dried over Na₂SO₄, filtered and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give methyl 3-(thiazol-5-yl)benzoate.

3-(thiazol-5-yl)benzoic Acid

To a mixture of methyl 3-(thiazol-5-yl)benzoate (600 mg, 2.74 mmol) in 4:1:1 THF/MeOH/H2O (6 mL) was added LiOH (98 mg, 4.10 mmol) and the resulting mixture was stirred at rt for 3 hr. The mixture was partially concentrated in vacuo to remove the volatile organics and then acidified with 1M HCl to pH=1 causing a precipitate to form. The suspension was filtered and the solid that was collected was washed with H₂O and dried under high vacuum to give 3-(thiazol-5-yl)benzoic acid.

General Procedure O Synthesis of Racemic trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentan-1-ol

trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentan-1-ol (Racemic)

To a solution of cyclopentene oxide (2.03 g, 24.1 mmol) in MeCN (10 mL) was added 3,5-dimethyl-1H-pyrazole (2.78 g, 28.96 mmol) then Cs₂CO₃ (9.43 g, 28.96 mmol) and the resulting mixture was heated to reflux for 16 hours. The mixture was allowed to cool to room temperature and then filtered and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentan-1-ol (racemic).

General Procedure R Preparation of tert-butyl 3-hydroxy-3-(4-isopropylphenyl)azetidine-1-carboxylate

tert-butyl 3-hydroxy-3-(4-isopropylphenyl)azetidine-1-carboxylate

A solution of tert-butyl 3-oxoazetidine-1-carboxylate (793 mg, 4.63 mmol) in THF (4 mL) at −78° C. was added (4-isopropylphenyl)magnesium bromide (0.5 M in THF, 5 mL, 5.0 mmol) dropwise and the resulting mixture was stirred for 30 minutes at −78° C. The mixture was diluted with sat. aq. NH₄Cl and extracted with EtOAc. The combined organic extracts were dried over Na₂SO₄, filtered, and concentrated in vacuo. The crude residues was purified by normal phase silica gel chromatography to give tert-butyl 3-hydroxy-3-(4-isopropylphenyl)azetidine-1-carboxylate.

SYNTHETIC EXAMPLES

The chemical reactions in the Synthetic Examples described can be readily adapted to prepare a number of other compounds of the invention, and alternative methods for preparing the compounds of this invention are deemed to be within the scope of this invention. For example, the synthesis of non-exemplified compounds according to the invention can be successfully performed by modifications apparent to those skilled in the art, e.g., by appropriately protecting interfering groups, by utilizing other suitable reagents known in the art other than those described, or by making routine modifications of reaction conditions. Alternatively, other reactions disclosed herein or known in the art will be recognized as having applicability for preparing other compounds of the invention. In the following Examples, certain compounds are noted as racemic, as separated isomers, or with unassigned absolute stereochemistry at some stereocenters, and the like. For some compounds, further separation of isomers and/or assignment of absolute stereochemistry was performed. The assigned stereochemistry of such compounds is shown in the structures as depicted in FIG. 1, Table 2.

Example 1, Compound 1 Two Syntheses of N-(2-chloro-3-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine Example 1a

Compound 1a-a: To a solution of tert-butyl 7-(4-hydroxybutyl)-3,4-dihydro-2H-1,8-naphthyridine-1-carboxylate (11 g, 35.90 mmol) in DMF (150 mL) was added NaH (2.15 g, 53.85 mmol, 60% suspension in mineral oil) at 0° C. under N₂. The mixture was stirred for 30 min at 0° C., then 3-bromoprop-1-ene (5.21 g, 43.08 mmol, 1.2 eq) was added into the mixture at 0° C. The mixture was stirred for 10 hrs at 20° C. TLC (Petroleum ether/Ethyl acetate=3/1, R_(f)=0.1) indicated tert-butyl 7-(4-hydroxybutyl)-3,4-dihydro-2H-1,8-naphthyridine-1-carboxylate (11 g, 35.90 mmol) was consumed completely. LCMS indicated desired M+H⁺ was detected. The mixture was quenched by NH4Cl solution and extracted by EtOAc (3×50 mL). The organic layer was dried by brine and Na₂SO₄, filtered and concentrated under reduced pressure to give a residue. The crude product was purified by column chromatography (SiO₂, Petroleum ether/Ethyl acetate=50/1 to 5:1) to give compound 1a-a (6 g, 16.64 mmol, 46.36% yield) as a colourless oil. LCMS (ESI+): m/z=347.3(M+H)⁺, RT=0.943 min.

¹H NMR (400 MHz, CDCl3) δ ppm 7.29 (s, 1H) 6.82 (d, J=7.50 Hz, 1H) 5.92 (td, J=11.19, 5.18 Hz, 1H) 5.11-5.32 (m, 2H) 3.96 (br d, J=5.51 Hz, 2H) 3.75 (t, J=5.95 Hz, 2H) 3.47 (t, J=6.50 Hz, 2H) 2.70-2.77 (m, 4H) 1.89-1.95 (m, 2H) 1.81 (br t, J=7.83 Hz, 2H) 1.64-1.72 (m, 2H) 1.52 (s, 9H).

Compound 1a-b: To a solution of compound 1a-a (3 g, 8.66 mmol) in MeOH (25 mL) and H₂O (25 mL) at 20° C. was added NaIO4 (4.63 g, 21.65 mmol, 1.2 mL) and OsO₄ (44.03 mg, 173.18 umol, 8.99 uL). The resulting suspension was stirred at 20° C. for 10 hrs. TLC (Petroleum ether/Ethyl acetate=l/1, R_(f)=0.6) indicated compound 1a-a was consumed completely and a new spot was detected. The mixture was quenched by Na₂SO₃ solution (150 mL) and extracted by EtOAc (3×60 mL). The organic layer was dried by brine and Na₂SO₄, filtered and concentrated under reduced pressure to give compound 1a-b (2.7 g, 7.75 mmol, 89.5% yield) as a yellow oil. The crude product was used for next step without further purification.

¹H NMR (400 MHz, CDCl3) δ ppm 9.73 (s, 1H) 7.29 (br d, J=7.72 Hz, 1H) 6.80-6.83 (m, 1H) 3.74 (br d, J=5.95 Hz, 2H) 3.57 (br t, J=6.39 Hz, 2H) 3.44-3.49 (m, 2H) 2.72 (br t, J=6.28 Hz, 4H) 1.90-1.94 (m, 2H) 1.70-1.84 (m, 4H) 1.52 (s, 9H)

Compound 1a-c: To a solution of compound 1a-b (2.7 g, 7.75 mmol) in DCM (30 mL) was added methyl 2-(benzyloxycarbonylamino)-2-dimethoxyphosphoryl-acetate (2.82 g, 8.52 mmol) followed by DBU (1.30 g, 8.52 mmol, 1.28 mL). The resulting suspension was stirred at 20° C. for 1 hr. TLC (Petroleum ether/Ethyl acetate=l/l, R_(f)=0.26) indicated compound 1a-b was consumed completely and one major new spot was detected. The mixture was quenched by NH4Cl solution and extracted with EtOAc (3×40 mL). The organic layer was dried by brine and Na₂SO₄, filtered and concentrated under reduced pressure to give a residue. The crude product was purified by column chromatography (SiO₂, Petroleum ether/Ethyl acetate=10/1 to 1:1). The product compound 1a-c (3 g, 5.42 mmol, 94.40% yield) was obtained as a brown oil.

¹H NMR (400 MHz, CDCl3) δ ppm 7.32-7.39 (m, 5H) 6.80 (d, J=7.50 Hz, 1H) 6.68 (br s, 1H) 6.57 (t, J=5.62 Hz, 1H) 5.14 (s, 2H) 4.15 (d, J=5.51 Hz, 2H) 3.79 (s, 3H) 3.74 (d, J=5.95 Hz, 2H) 3.47 (t, J=6.50 Hz, 2H) 2.70-2.75 (m, 4H) 1.92 (quin, J=6.34 Hz, 2H) 1.76-1.84 (m, 2H) 1.63-1.68 (m, 2H) 1.52 (s, 10H).

Compound 1a-d: The solvent MeOH (30 mL) was added Pd(OH)₂/C (507.31 mg, 722.48 umol, 20% purity) and degassed under vacuum and purged with H₂ several times. The mixture was stirred under H₂ (50 psi) at 50° C. for 4 hrs. Then compound 1a-c (2 g, 3.61 mmol) was added into the mixture. The suspension was degassed under vacuum and purged with H₂ for 3 times. The mixture was stirred under H₂ (50 psi) at 50° C. for 4 hrs. LCMS indicated desired MS was detected. The mixture was filtered and concentrated under reduced pressure. The product compound 1a-d (1.4 g, crude) was obtained as a yellow oil, which was used for next step without further purification. LCMS (ESI+): m/z=422.3 (M+H)⁺; RT=0.752 min.

Compound 1a-e: To a mixture of 2-chloro-3-fluoro-benzoic acid (807.50 mg, 4.63 mmol) in DMF (15 mL) was added HOBt (721.25 mg, 5.34 mmol), EDCI (1.02 g, 5.34 mmol) and DIEA (1.38 g, 10.68 mmol, 1.86 mL). Then compound 1a-d (1.5 g, 3.56 mmol) was added into the mixture. The mixture was stirred at 20° C. for 5 hrs. TLC (Petroleum ether/Ethyl acetate=0/1, R_(f)=0.2) indicated compound 1a-d was consumed completely. The mixture was extracted by H₂O (40 mL) and EtOAc (3×20 mL). The organic layer was dried by brine and Na₂SO₄, filtered and concentrated under reduced pressure. The crude product was purified by prep-HPLC (neutral conditions) to give compound 1a-e (1.3 g, 2.2 mmol, 61.69% yield, 97.61% purity) as a brown oil. HPLC purification conditions: column: Phenomenex Gemini C18 250×50 mm×10 um; mobile phase: [water (10 mM NH4HCO3)-ACN]; B %: 40%-70%, 20 min. LCMS (ESI+): m/z=578.4 (M+H)⁺; RT=1.038 min.

Example 1a: To a mixture of compound 1a-e (500 mg, 864.94 umol) was added HCl (4 M, 3.24 mL, 15 eq). The mixture was stirred at 70° C. for 10 hrs. LCMS indicated desired M+H⁺ was detected. The mixture was freeze-dried directly to give Example 1a (304.47 mg, 587.12 umol, 67.88% yield, 96.492% purity, HCl) which was delivered without any further purification. LCMS (ESI+): m/z=464.1(M+H)⁺, RT=2.450 min; HPLC purity: 96.492%, RT=6.566 min; Chiral SFC purity: 52.72%, ee value: 0%, RT=3.447 min.

¹H NMR (400 MHz, MeOH-d₄) δ ppm 7.57 (d, J=7.28 Hz, 1H) 7.32-7.47 (m, 3H) 6.65 (d, J=7.28 Hz, 1H) 3.54-3.64 (m, 3H) 3.43-3.50 (m, 3H) 2.80 (t, J=6.28 Hz, 2H) 2.70-2.77 (m, 2H) 2.29 (ddt, J=14.08, 9.40, 4.80, 4.80 Hz, 1H) 1.62-2.00 (m, 8H).

Example 1b

Compound 1b-a: To a suspension of 4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butanoic acid hydrochloride (1.23 g, 4.79 mmol, 1.0 equiv) in THF was added LiAlH₄ (1.0M in THF, 10.6 mL, 10.6 mmol) dropwise and the resulting mixture was refluxed overnight. The mixture was then cooled in an ice bath and to this was slowly added H₂O (400 μL), then aqueous 1.0 M NaOH (400 μL), then H₂O (400 μL) again and stirred for 15 minutes and then a large excess of MgSO₄ was added and stirred for an additional 30 minutes. The resulting organic mixture was filtered and then concentrated in vacuo to provide compound 1b-a.

Compound 1b-b: To a stirring suspension of NaH (60 wt % dispersion in mineral oil, 238 mg, 5.96 mmol) in THF (8.2 mL) at 0° C. was added a solution of 1b-a (820 mg, 3.98 mmol) in THF (4.1 mL) dropwise. Upon completion of the addition, the ice bath was removed and the resulting mixture was stirred at room temperature for 30 minutes, at which time, allyl bromide (400 μL, 4.62 mmol) was added dropwise. The suspension was stirred for an additional 6 hrs at room temperature and then carefully diluted with H₂O and EtOAc. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were dried over MgSO₄, filtered, and concentrated in vacuo. The crude residue was purified by silica gel chromatography to provide compound 1b-b.

Compound 1b-c: To a solution of 1b-b (582 mg, 2.36 mmol) in 3:1 THF/H₂O (6 mL) at room temperature was added NaIO4 (2.02 g, 9.44 mmol) followed by OsO₄ (2.5 wt % in t-BuOH, 480 μL, 0.05 mmol). The resulting suspension was stirred at room temperature for 5 hrs and then diluted with 1:1 sat. aq. NaHCO3/sat. aq. Na2S2O3 and EtOAc and then stirred for 1 hr at room temperature. The biphasic mixture was filtered through a small pad of Celite and then the layers were separated. The aqueous layer was extracted with EtOAc and the combined organic extracts were dried over MgSO4, filtered, and concentrated in vacuo to provide a crude residue that was used without further purification.

To the crude residue obtained from the previous reaction (586 mg, 2.36 mmol) in CH2Cl2 (6 mL) at room temperature was added methyl 2-(((benzyloxy)carbonyl)amino)-2-(dimethoxyphosphoryl)acetate (860 mg, 2.60 mmol) followed by DBU (391 μL, 2.60 mmol) and stirred for 30 minutes at room temperature. The mixture was diluted with sat. aq. NH4Cl and stirred for 5 minutes at room temperature. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were dried over MgSO4, filtered, and concentrated in vacuo. The crude residue was purified by silica gel chromatography to provide compound 1b-c.

Compound 1b-d: A flask containing 1b-c (497 mg, 1.10 mmol) and 20 wt % Pd(OH)2 on carbon (100 mg) was diluted with MeOH (5 ml) and then evacuated and backfilled with H2 for 3 cycles and then stirred under an H2 atmosphere for 3 hrs. The resulting mixture was filtered through a pad of Celite and then concentrated in vacuo to give compound 1b-d (352 mg) that was used without further purification.

Compound 1b-e: A flask containing 1b-d (50.0 mg, 0.15 mmol) was charged with 2-chloro-3-fluorobenzoic acid (40.7 mg, 0.23 mmol) and then diluted with 10:1 THF/DMF (2.0 mL). To this was then added DIPEA (81 μL, 0.47 mmol) followed by HATU (89 mg, 0.23 mmol) and stirred for 30 minutes at room temperature and then concentrated in vacuo. The crude residue was purified by silica gel chromatography to provide compound 1b-e.

Example 1b: To a solution of 1b-e (61 mg, 0.13 mmol) in 4:1:1 THF/MeOH/H2O (2.0 mL) was added LiOH (9 mg, 0.39 mmol) and the resulting mixture was stirred at room temperature for 30 minutes. The mixture was then neutralized with AcOH and then and purified by preparative reverse phase HPLC to give Example 1b as the trifluoroacetate salt. LCMS theoretical m/z=464.9 [M+H]+, found: 464.9.

Example 2, Compound 8 2-(2-ethylbutanamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic Acid

Compound 2a: two batches in parallel: To a mixture of ethyl 4-oxopentanoate (50 g, 346.82 mmol, 49.50 mL) and 2-aminopyridine-3-carbaldehyde (42.35 g, 346.82 mmol) in EtOH (800 mL) was added L-proline (19.96 g, 173.41 mmol). The mixture was refluxed at 85° C. for 12 hrs. LCMS indicated the reaction was completed. TLC (Petroleum ether/Ethyl acetate=2:1, R_(f)=0.31) was the spot of product. The mixture was combined and concentrated under reduced pressure. The mixture was extracted by H₂O (1000 mL) and EtOAc (3×800 mL), washed with brine and dried with Na₂SO₄, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography (SiO₂, Petroleum ether/Ethyl acetate=10/1 to 1:1) to give compound 2a (60 g, 240.85 mmol, 34.72% yield, 92.4% purity) as a yellow solid. LCMS (ESI+): m/z=231.1(M+H)⁺, RT=0.68 min. ¹H NMR (400 MHz, CDCl3) δ ppm 9.08 (dd, J=4.19, 1.98 Hz, 1H) 8.07-8.19 (m, 2H) 7.42-7.48 (m, 2H) 4.12 (q, J=7.06 Hz, 2H) 3.32-3.39 (m, 2H) 3.06 (t, J=7.28 Hz, 2H) 1.23 (t, J=7.17 Hz, 3H).

Compound 2b: two batches were processed in parallel: To a solution of compound 2a (26 g, 112.91 mmol) in EtOH (300 mL) was added Pd/C (3 g, 10%) under N₂. The suspension was degassed under vacuum and purged with H₂ several times. The mixture was stirred under H2 (50 psi) at 20° C. for 10 hrs. TLC (Petroleum ether/Ethyl acetate=0:1, R_(f)=0.3) indicated the compound 5a was consumed completely and a new spot was detected. LCMS indicated desired MS was detected. The mixture was filtered and concentrated under reduced pressure to give compound 2b (46 g, 196.33 mmol, 86.94% yield) as a white solid. The crude product was used for next step with further purification. LCMS (ESI+): m/z=235.1(M+H)⁺, RT=0.772 min.

Compound 2c: A mixture of compound 2b (46 g, 196.33 mmol) and Boc₂O (100 mL) was stirred at 40° C. for 15 hrs. TLC (Petroleum ether/Ethyl acetate=2:1, R_(f)=0.11) indicated compound 2c was formed. The mixture was not worked up but evaporated and applied to a column of silica gel. The crude product was purified by column chromatography (SiO₂, Petroleum ether/Ethyl acetate=100/1 to 5:1) to give compound 2c (32 g, 95.69 mmol, 48.74% yield) as a white solid. ¹H NMR (400 MHz, CDCl3) δ ppm 7.33 (d, J=7.72 Hz, 1H) 6.88 (d, J=7.72 Hz, 1H) 4.17 (q, J=7.06 Hz, 2H) 3.76-3.81 (m, 2H) 3.04-3.10 (m, 2H) 2.81-2.86 (m, 2H) 2.76 (t, J=6.62 Hz, 2H) 1.95 (quin, J=6.34 Hz, 2H) 1.51 (s, 9H) 1.28 (t, J=7.06 Hz, 3H).

Compound 2d: To a solution of compound 2c (14 g, 41.86 mmol) in THF (140 mL) was added LiBH₄ (1.82 g, 83.73 mmol) in several portions at 0° C. under N₂. The reaction mixture was warmed to 15° C. for 1 hr. The reaction mixture was stirred at 40° C. for 12 hrs. TLC (Petroleum ether/Ethyl acetate=1:1, R_(f)=0.61) indicated compound 2c was consumed completely. The mixture was poured into the saturated NH4Cl solution (500 mL) and was extracted by EtOAc (3×300 mL). The organic layer was dried by brine and Na₂SO₄, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography (SiO₂, Petroleum ether/Ethyl acetate=0:1) to give compound 2d (18 g, 61.57 mmol, 73.53% yield) as a white solid. ¹H NMR (400 MHz, CDCl3) δ ppm 7.31 (d, J=7.72 Hz, 1H) 6.83 (d, J=7.72 Hz, 1H) 3.74-3.78 (m, 2H) 3.69 (br t, J=5.62 Hz, 2H) 2.88-2.93 (m, 2H) 2.73 (t, J=6.50 Hz, 2H) 1.89-1.96 (m, 4H) 1.54 (s, 9H).

Compound 2e: To a mixture of compound 2d (3 g, 10.26 mmol) in DMF (30 mL) was added NaH (2.46 g, 61.57 mmol, 60% purity) at 0° C. Then the mixture was stirred at 0° C. for 0.5 hr. Then 5-bromopent-1-ene (6.12 g, 41.04 mmol) was added into the mixture at 0° C. The mixture was warmed to 15° C. for 12 hrs. LCMS indicated desired MS was detected. TLC (Petroleum ether/Ethyl acetate=3/1, R_(f)=0.18) indicated compound 2d was consumed. The mixture was poured into NH4Cl solution (50 mL) and extracted by EtOAc (3×30 mL). The organic layer was dried by brine and Na₂SO₄, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography (SiO₂, Petroleum ether/Ethyl acetate=100/1 to 10:1) to give compound 2e (2.8 g, 7.77 mmol, 75.70% yield) as a yellow oil. LCMS (ESI+): m/z=361.3 (M+H)⁺; RT: 1.016 min. ¹H NMR (400 MHz, CDCl3) δ ppm 7.25 (d, J=3.09 Hz, 1H) 6.80 (d, J=7.72 Hz, 1H) 5.80 (ddt, J=17.03, 10.31, 6.61, 6.61 Hz, 1H) 4.92 -5.02 (m, 2H) 3.72 (d, J=5.95 Hz, 2H) 3.40-3.44 (m, 4H) 2.69-2.77 (m, 4H) 2.08-2.13 (m, 2H) 1.97-2.02 (m, 2H) 1.88-1.92 (m, 2H) 1.62-1.67 (m, 2H) 1.49 (s, 9H).

Compound 2f: Ozone was bubbled into a solution of Compound 2e (2.8 g, 7.77 mmol) in DCM (20 mL) and MeOH (10 mL) at −78° C. for 30 minutes. After excess 03 was purged by 02, Me₂S (4.83 g, 77.67 mmol, 5.70 mL) was added at −78° C. The mixture was stirred for 12 hrs at 20° C. LCMS indicated desired MS was detected. TLC (Petroleum ether/Ethyl acetate=1:1, R_(f)=0.6) indicated compound 2e was consumed completely. The mixture was concentrated under reduced pressure. The crude product was purified by column chromatography (SiO₂, Petroleum ether/Ethyl acetate=30:1 to 8:1) to give compound 2f (1.4 g, 3.86 mmol, 49.73% yield) as a brown oil. LCMS (ESI+): m/z=363.3 (M+H)⁺; RT=0.853 min.

Compound 2g: To a solution of compound 2f (1.4 g, 3.86 mmol, 1 eq) in THF (10 mL) was added 2-methylpropane-2-sulfinamide (514.95 mg, 4.25 mmol) and tetraethoxytitanium (2.64 g, 11.59 mmol, 2.40 mL). The mixture was stirred at 50° C. for 12 hrs. LCMS indicated the desired MS. The mixture was concentrated under reduced pressure to give compound 2g (1.7 g, crude) as brown oil. The crude product was used directly for next step without purification. LCMS (ESI+): m/z=466.3 (M+H)+, RT: 0.991 min.

Compound 2h: To a mixture of compound 2g (1.7 g, 3.65 mmol) in dried THF (20 mL) was added NaCN (536.75 mg, 10.95 mmol). The mixture was stirred at 40° C. for 12 hrs. NaCN (536.75 mg, 10.95 mmol) and i-PrOH (658.19 mg, 10.95 mmol, 838.46 uL) was added into the mixture with stirring for 16 hrs at 55° C. LCMS indicated desired M+H was detected. TLC (Petroleum ether/Ethyl acetate=1:1, R_(f)=0.72) indicated compound 2g was consumed. The mixture was extracted by H₂O (50 mL) and EtOAc (3×30 mL). The organic layer was dried by brine and Na₂SO₄, filtered and concentrated under reduced pressure. The H₂O layer was quenched by NaClO solution. The crude product was purified by column chromatography (SiO₂, Petroleum ether/Ethyl acetate=10:1 to 1:1) to give compound 2h (450 mg, 850.45 umol, 23.29% yield) as yellow oil. LCMS (ESI+): m/z=493.4 (M+H)⁺, RT=0.958 min.

Compound 2i: To a mixture of compound 2h (450 mg, 913.38 umol) in HCl/MeOH (5 mL) was stirred at 50° C. for 16 hrs. LCMS indicated desired MS was detected. The mixture was concentrated under reduced pressure to give the crude compound 2i (360 mg, crude) as a brown oil, which was used directly for next step without further purification. LCMS (ESI+): m/z=322.3 (M+H)⁺, RT=0.628 min.

Compound 2j: To a mixture of 2-ethylbutanoic acid (79.53 mg, 684.7 umol, 86.26 uL) in DMF (3 mL) was added HOBt (92.52 mg, 684.70 umol), EDCI (131.26 mg, 684.7 umol) and DIEA (176.98 mg, 1.37 mmol, 238.52 uL). Then compound 2i (180 mg, 456.46 umol) was added into the mixture. The mixture was stirred at 15° C. for 10 hrs. LCMS indicated desired MS was detected. The mixture was extracted by H₂O (20 mL) and EtOAc (3×10 mL). The organic layer was dried by brine and Na₂SO₄, filtered and concentrated under reduced pressure. The crude product was purified by prep-TLC (SiO₂, Ethyl acetate/MeOH=10:1) to give compound 2j (65 mg, 154.93 umol, 33.94% yield) as a yellow oil. LCMS (ESI+): m/z=419.56 (M+H)⁺, RT=0.855 min.

Example 2: To a mixture of compound 2j (65 mg, 154.92 umol) was added HCl (4 M, 193.66 uL). The mixture was stirred at 70° C. for 12 hrs. LCMS indicated desired MS was detected. The mixture was concentrated under reduced pressure. The crude product was purified by prep-HPLC (TFA condition) to give Example 2 (40 mg, 76.13 umol, 49.14% yield, 98.887% purity, TFA) as a colourless oil.

HPLC purification conditions: column: Luna C_(18 100×30 5)u; mobile phase: [water (0.1% TFA)-ACN]; B %: 1%-40%, 5 min.

¹H NMR (400 MHz, MeOH-d₄) δ ppm 7.59 (d, J=7.50 Hz, 1H) 6.64 (d, J=7.28 Hz, 1H) 4.46 (dd, J=9.26, 4.85 Hz, 1H) 3.44-3.53 (m, 6H) 2.78-2.85 (m, 4H) 2.14 (tt, J=9.59, 4.96 Hz, 1H) 1.91-1.98 (m, 5H) 1.44-1.75 (m, 7H) 0.87-0.95 (m, 6H); LCMS (ESI+): m/z=406.2(M+H)⁺, RT=2.336 min; HPLC purity: 98.887%, RT=6.242 min; Chiral SFC purity: 52.72%, ee value: 5.44%, RT=2.013 min.

Example 3, Compound 9 2-(2-chloro-3-fluorobenzamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic Acid

Example 3 was prepared by the same procedure used to prepare Example 2 with the exception that the acid was replaced by 2-chloro-3-fluorobenzoic acid in the reaction with intermediate 2i.

HPLC purification conditions: column: Phenomenex Synergi C18 100*21.2 mm*4 um; mobile phase: [water (0.1% TFA)-ACN]; B %: 15%-45%, 10 min

¹H NMR (400 MHz, MeOH-d₄) δ ppm 7.57 (d, J=7.50 Hz, 1H) 7.30-7.43 (m, 3H) 6.63 (d, J=7.28 Hz, 1H) 4.63 (dd, J=9.26, 4.85 Hz, 1H) 3.47-3.52 (m, 6H) 2.78-2.83 (m, 4H) 2.01-2.09 (m, 1H) 1.92-1.97 (m, 4H) 1.71-1.87 (m, 3H); HPLC purity: 99.041%, RT: 6.480 min; LCMS (ESI+): m/z=464.1 (M+H)⁺, RT=2.399 min; Chiral SFC purity: 52.42%, ee value: 4.84%, RT=3.870 min.

Example 4, Compound 2

N-(1-methyl-1H-indazole-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 1-methyl-1H-indazole-4-carboxylic acid. LCMS theoretical m/z=466.2. [M+H]+, found 466.2.

Example 5, Compound 3

N-(2-ethylbutanoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 2-ethylbutanoic acid. LCMS theoretical m/z=406.3 [M+H]+, found: 406.3.

Example 6, Compound 4

N-benzoyl-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with benzoic acid. LCMS theoretical m/z=412.2 [M+H]+, found: 412.2.

Example 7, Compound 5

N-(4,4-difluorocyclohexane-1-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 4,4-difluorocyclohexane-1-carboxylic acid. LCMS theoretical m/z=454.3 [M+H]+, found: 454.3.

Example 8, Compound 6

N-pentanoyl-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with butanoic acid. LCMS theoretical m/z=392.3 [M+H]+, found: 392.3.

Example 9, Compound 7

N-(3-fluoro-5-(trifluoromethyl)benzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 3-fluoro-5-(trifluoromethyl)benzoic acid. LCMS theoretical m/z=498.2 [M+H]+, found: 498.2.

Example 10, Compound 15

N-(3-fluoro-5-(trifluoromethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme H using General Procedure I with 3-fluoro-5-(trifluoromethyl)benzoic acid. LCMS theoretical m/z=524.2 [M+H]+, found 524.3.

Example 11, Compound 18

N-pentanoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme H using General Procedure I with pentanoic acid. LCMS theoretical m/z=418.3 [M+H]+, found 418.3.

Example 12, Compound 19

N-(tert-butoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme H through intermediate 13H, followed by General Procedure N. LCMS theoretical m/z=434.3 [M+H]+, found 434.3.

Example 12A, Compound 19

N-(tert-butoxycarbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A through intermediate 13A, followed by General Procedure N. LCMS theoretical m/z=434.3 [M+H]+, found 434.3.

Example 13, Compound 22

N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C through intermediate 7C, followed by General Procedure N. LCMS theoretical m/z=408.2 [M+H]+, found: 408.2.

Example 14, Compound 14

N-(2-chloro-3-fluorobenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme B using General Procedure I with 2-chloro-3-fluorobenzoic acid. LCMS theoretical m/z=490.2 [M+H]+, found 490.2.

Example 15, Compound 24

N-(4-fluorobenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme B using General Procedure I with 4-fluorobenzoic acid. LCMS theoretical m/z=456.2 [M+H]+, found 456.2.

Example 16, Compound 24

N-(4-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 4-fluorobenzoic acid. LCMS theoretical m/z=456.2 [M+H]+, found 456.2.

Example 17, Compound 25

N-(4-chlorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 4-chlorobenzoic acid. LCMS theoretical m/z=472.2 [M+H]+, found 472.2.

Example 18, Compound 19

N-(tert-butoxycarbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was used in General Procedure N. LCMS theoretical m/z=434.3 [M+H]+, found 434.3.

Example 19, Compound 26

N-(3-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-fluorobenzoic acid. LCMS theoretical m/z=456.2 [M+H]+, found 456.2.

Example 20, Compound 27

N-(3-chlorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-chlorobenzoic acid. LCMS theoretical m/z=472.2 [M+H]+, found 472.2.

Example 21, Compound 28

N-(2-chlorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2-chlorobenzoic acid. LCMS theoretical m/z=472.2 [M+H]+, found 472.2.

Example 22, Compound 29

N-(2-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2-fluorobenzoic acid. LCMS theoretical m/z=456.2 [M+H]+, found 456.2.

Example 23, Compound 30

N-(2,3-difluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2,3-difluorobenzoic acid. LCMS theoretical m/z=474.2 [M+H]+, found 474.2.

Example 24, Compound 31

N-(2,4-difluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2,4-difluorobenzoic acid. LCMS theoretical m/z=474.2 [M+H]+, found 474.2.

Example 25, Compound 32

N-(2-chloro-4-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2-chloro-4-difluorobenzoic acid. LCMS theoretical m/z=490.2 [M+H]+, found 490.2.

Example 26, Compound 33

N-(3-chloro-5-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-chloro-5-fluorobenzoic acid. LCMS theoretical m/z=490.2 [M+H]+, found 490.2.

Example 27, Compound 34

N-(3-chloro-2-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-chloro-2-fluorobenzoic acid. LCMS theoretical m/z=490.2 [M+H]+, found 490.2.

Example 28, Compound 35

N-(3,5-difluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3,5-difluorobenzoic acid. LCMS theoretical m/z=474.2 [M+H]+, found 474.2.

Example 29, Compound 36

N-(3,4-difluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3,4-difluorobenzoic acid. LCMS theoretical m/z=474.2 [M+H]+, found 474.2.

Example 30, Compound 37

N-(2,3-dichlorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2,3-dichlorobenzoic acid. LCMS theoretical m/z=506.2 [M+H]+, found 506.2.

Example 31, Compound 38

N-(2-chloro-6-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2-chloro-5-fluorobenzoic acid. LCMS theoretical m/z=490.2 [M+H]+, found 490.2.

Example 32, Compound 39

N-(2,6-difluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2,6-difluorobenzoic acid. LCMS theoretical m/z=474.2 [M+H]+, found 474.2.

Example 33, Compound 40

N-(2,5-difluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2,5-difluorobenzoic acid. LCMS theoretical m/z=474.2 [M+H]+, found 474.2.

Example 34, Compound 41

N-(3,4-dichlorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3,4-dichlorobenzoic acid. LCMS theoretical m/z=506.2 [M+H]+, found 506.2.

Example 35, Compound 42

N-picolinoyl-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with picolinic acid. LCMS theoretical m/z=439.2 [M+H]+, found 439.2.

Example 36, Compound 43

N-nicotinoyl-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with nicotinic acid. LCMS theoretical m/z=439.2 [M+H]+, found 439.3.

Example 37, Compound 44

N-isonicotinoyl-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with isonicotinic acid. LCMS theoretical m/z=439.2 [M+H]+, found 439.3.

Example 38, Compound 45

N-(1-methyl-1H-indazole-4-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 1-methyl-1H-indazole-4-carboxylic acid. LCMS theoretical m/z=492.3 [M+H]+, found 492.3.

Example 39, Compound 46

N-(2-methyl-2H-indazole-6-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2-methyl-2H-indazole-6-carboxylic acid. LCMS theoretical m/z=492.3 [M+H]+, found 492.3.

Example 40, Compound 47

N-(2-methyl-2H-indazole-5-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2-methyl-2H-indazole-5-carboxylic acid. LCMS theoretical m/z=492.3 [M+H]+, found 492.3.

Example 41, Compound 48

N-(1-methyl-1H-pyrrolo[2,3-b]pyridine-4-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 1-methyl-1H-pyrrolo[2,3-b]pyridine-4-carboxylic acid. LCMS theoretical m/z=492.3 [M+H]+, found 492.3.

Example 42, Compound 49

N—((R)-3-hydroxy-2-phenylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with (R)-3-hydroxy-2-phenylpropanoic acid and General Procedure N followed by preparative HPLC to afford the first eluting of two diastereomers as a single stereoisomer. The amino acid stereochemistry was unassigned. LCMS theoretical m/z=482.3 [M+H]+, found 482.3.

Example 43, Compound 49

N—((R)-3-hydroxy-2-phenylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with (R)-3-hydroxy-2-phenylpropanoic acid and General Procedure N followed by preparative HPLC to afford the second eluting of two diastereomers as a single stereoisomer. The amino acid stereochemistry was unassigned. LCMS theoretical m/z=482.3 [M+H]+, found 482.3.

Example 44, Compound 50

N-(2-ethylbutanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2-ethylbutanoic acid. LCMS theoretical m/z=432.3 [M+H]+, found 432.3.

Example 45, Compound 51

N-(3-ethylpentanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-ethylpentanoic acid. LCMS theoretical m/z=446.3 [M+H]+, found 446.3.

Example 46, Compound 49

N—((S)-3-hydroxy-2-phenylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with (S)-3-hydroxy-2-phenylpropanoic acid and General Procedure N followed by preparative HPLC to afford the first eluting of two diastereomers as a single stereoisomer. The amino acid stereochemistry was unassigned. LCMS theoretical m/z=482.3 [M+H]+, found 482.3.

Example 47, Compound 49

N—((S)-3-hydroxy-2-phenylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with (S)-3-hydroxy-2-phenylpropanoic acid and General Procedure N followed by preparative HPLC to afford the second eluting of two diastereomers as a single stereoisomer. The amino acid stereochemistry was unassigned. LCMS theoretical m/z=482.3 [M+H]+, found 482.3.

Example 48, Compound 52

N-(1-methyl-1H-pyrrolo[2,3-b]pyridine-5-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 1-methyl-1H-pyrrolo[2,3-b]pyridine-5-carboxylic acid. LCMS theoretical m/z=492.3 [M+H]+, found 492.3.

Example 49, Compound 53

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(3-(thiazol-5-yl)benzoyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-(thiazol-5-yl)benzoic acid. LCMS theoretical m/z=521.2 [M+H]+, found 521.2.

Example 50, Compound 54

N-(3-(hydroxymethyl)benzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-(hydroxymethyl)benzoic acid. LCMS theoretical m/z=468.2. [M+H]+, found 468.3.

Example 51, Compound 55

N-(quinoline-5-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with quinoline-5-carboxylic acid. LCMS theoretical m/z=489.2. [M+H]+, found 489.3.

Example 52, Compound 56

N-(2-cyclopropylbenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 2-cyclopropylbenzoic acid. LCMS theoretical m/z=478.3. [M+H]+, found 478.3.

Example 53, Compound 57

N-(quinoline-7-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with quinoline-7-carboxylic acid. LCMS theoretical m/z=489.2. [M+H]+, found 489.3.

Example 54, Compound 58

N-(quinoline-6-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with quinoline-6-carboxylic acid. LCMS theoretical m/z=489.2. [M+H]+, found 489.3.

Example 55, Compound 59

N-(quinoline-8-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with quinoline-8-carboxylic acid. LCMS theoretical m/z=489.2. [M+H]+, found 489.3.

Example 56, Compound 60

N-(3-cyclopropylbenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-cyclopropylbenzoic acid. LCMS theoretical m/z=478.3. [M+H]+, found 478.3.

Example 57, Compound 61

N-(4-cyclopropylbenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-, 8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 4-cyclopropylbenzoic acid. LCMS theoretical m/z=478.3. [M+H]+, found 478.3.

Example 58, Compound 44

N-isonicotinoyl-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-D-homoserine

Isomer D1 was employed in General Scheme D-2 using General Procedure I with isonicotinic acid. LCMS theoretical m/z=439.2. [M+H]+, found 439.3.

Example 59, Compound 51

N-(3-ethylpentanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-D-homoserine

Isomer D1 was employed in General Scheme D-2 using General Procedure I with 3-ethylpentanoic acid. LCMS theoretical m/z=446.3. [M+H]+, found 446.3.

Example 60, Compound 14

N-(2-chloro-3-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D1 was employed in General Scheme D-2 using General Procedure I with 2-chloro-3-fluorobenzoic acid. LCMS theoretical m/z=490.2. [M+H]+, found 490.2.

Example 61, Compound 53

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(3-(thiazol-5-yl)benzoyl)homoserine

Isomer D1 was employed in General Scheme D-2 using General Procedure I with 3-(thiazol-5-yl)benzoic acid. LCMS theoretical m/z=521.2. [M+H]+, found 521.2.

Example 62, Compound 44

N-isonicotinoyl-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with isonicotinic acid. LCMS theoretical m/z=439.2. [M+H]+, found 439.3.

Example 63, Compound 51

N-(3-ethylpentanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-ethylpentanoic acid. LCMS theoretical m/z=446.3. [M+H]+, found 446.3.

Example 64, Compound 14

N-(2-chloro-3-fluorobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-chloro-3-fluorobenzoic acid. LCMS theoretical m/z=490.2. [M+H]+, found 490.2.

Example 65, Compound 53

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(3-(thiazol-5-yl)benzoyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-(thiazol-5-yl)benzoic acid. LCMS theoretical m/z=521.2. [M+H]+, found 521.2.

Example 66, Compound 36

N-(3,4-difluorobenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme B using General Procedure I with 3,4-difluorobenzoic acid. LCMS theoretical m/z=474.2. [M+H]+, found 474.2.

Example 67, Compound 51

N-(3-ethylpentanoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme B using General Procedure I with 3-ethylpentanoic acid. LCMS theoretical m/z=446.3. [M+H]+, found 446.3.

Example 68, Compound 44

N-isonicotinoyl-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme B using General Procedure I with isonicotinic acid. LCMS theoretical m/z=439.2. [M+H]+, found 439.2.

Example 69, Compound 53

O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(3-(thiazol-5-yl)benzoyl)homoserine

Prepared according to General Scheme B using General Procedure I with 3-(thiazol-5-yl)benzoic acid. LCMS theoretical m/z=521.2. [M+H]+, found 521.2.

Example 70, Compound 49

N—((R)-3-hydroxy-2-phenylpropanoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme B using General Procedure I with (R)-3-hydroxy-2-phenylpropanoic acid, and General Procedure N to afford the title compound as the first eluting isomer. LCMS theoretical m/z=482.3. [M+H]+, found 482.3.

Example 71, Compound 49

N—((R)-3-hydroxy-2-phenylpropanoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme B using General Procedure I with (R)-3-hydroxy-2-phenylpropanoic acid, and General Procedure N to afford the title compound as the second eluting isomer. LCMS theoretical m/z=482.3. [M+H]+, found 482.3.

Example 72, Compound 62

N-(3-(1-methyl-1H-pyrazol-4-yl)benzoyl)-O-(trans-3-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with 3-(1-methyl-1H-pyrazol-4-yl)benzoic acid. LCMS theoretical m/z=518.2. [M+H]+, found 518.2.

Example 73, Compound 63

N-(3-(1-methyl-1H-pyrazol-4-yl)benzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 3-(1-methyl-1H-pyrazol-4-yl)benzoic acid. LCMS theoretical m/z=492.3. [M+H]+, found 492.3.

Example 74, Compound 64

N—((S)-2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with (S)-2-hydroxy-2-phenylacetic acid, and General Procedure N to afford the title compound as the first eluting isomer. LCMS theoretical m/z=442.2. [M+H]+, found 442.2.

Example 75, Compound 64

N—((S)-2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with (S)-2-hydroxy-2-phenylacetic acid, and General Procedure N to afford the title compound as the second eluting isomer. LCMS theoretical m/z=442.2. [M+H]+, found 442.2.

Example 76, Compound 64

N—((R)-2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with (R)-2-hydroxy-2-phenylacetic acid, and General Procedure N to afford the title compound as the first eluting isomer. LCMS theoretical m/z=442.2. [M+H]+, found 442.2.

Example 77, Compound 64

N—((R)-2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme C using General Procedure I with (R)-2-hydroxy-2-phenylacetic acid, and General Procedure N to afford the title compound as the second eluting isomer. LCMS theoretical m/z=442.2. [M+H]+, found 442.2.

Example 78, Compound 65

N—((S)-2-hydroxy-2-phenylacetyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with (S)-2-hydroxy-2-phenylacetic acid and General Procedure N to afford the title compound as the first eluting isomer. LCMS theoretical m/z=468.3. [M+H]+, found 468.3.

Example 79, Compound 65

N—((S)-2-hydroxy-2-phenylacetyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with (S)-2-hydroxy-2-phenylacetic acid, and General Procedure N to afford the title compound as the second eluting isomer. LCMS theoretical m/z=468.3. [M+H]+, found 468.3.

Example 80, Compound 65

N—((R)-2-hydroxy-2-phenylacetyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with (R)-2-hydroxy-2-phenylacetic acid, and General Procedure N to afford the title compound as the first eluting isomer. LCMS theoretical m/z=468.3. [M+H]+, found 468.3.

Example 81, Compound 65

N—((R)-2-hydroxy-2-phenylacetyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure I with (R)-2-hydroxy-2-phenylacetic acid, and General Procedure N to afford the title compound as the second eluting isomer. LCMS theoretical m/z=468.3. [M+H]+, found 468.3.

Example 82, Compound 66

N-(1-phenylcyclopropane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 1-phenylcyclopropane-1-carboxylic acid. LCMS theoretical m/z=478.3. [M+H]+, found 478.3.

Example 83, Compound 67

N-(2-methyl-2-phenylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 2-methyl-2-phenylpropanoic acid. LCMS theoretical m/z=480.3. [M+H]+, found 480.1.

Example 84, Compound 68

N-(1-phenylcyclobutane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 1-phenylcyclobutane-1-carboxylic acid. LCMS theoretical m/z=492.3. [M+H]+, found 492.2.

Example 85, Compound 69

N-(2,2-dimethyl-3-phenylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 2,2-dimethyl-3-phenylpropanoic acid. LCMS theoretical m/z=494.3. [M+H]+, found 494.2.

Example 86, Compound 19

N-(tert-butoxycarbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared using Scheme G-1 to afford Isomer G1, then using di-tert-butyl dicarbonate and triethylamine in DCM afforded methyl N-(tert-butoxycarbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserinate, which was subjected to General Procedure N. LCMS theoretical m/z=434.3. [M+H]+, found 434.3.

Example 87, Compound 70

N-(2-(4-fluorophenyl)-2-methylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 2-(4-fluorophenyl)-2-methylpropanoic acid. LCMS theoretical m/z=498.3. [M+H]+, found 498.3.

Example 88, Compound 71

N-(3-methyloxetane-3-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 3-methyloxetane-3-carboxylic acid. LCMS theoretical m/z=432.2. [M+H]+, found 432.2.

Example 89, Compound 72

N-(3-hydroxy-2,2-dimethylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 3-hydroxy-2,2-dimethylpropanoic acid. LCMS theoretical m/z=434.3. [M+H]+, found 434.2.

Example 90, Compound 73

N-(3-methoxy-2,2-dimethylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 3-methoxy-2,2-dimethylpropanoic acid. LCMS theoretical m/z=448.3. [M+H]+, found 448.3.

Example 91, Compound 74

N-(2-methyl-2-(pyridin-3-yl)propanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 2-methyl-2-(pyridin-3-yl)propanoic acid. LCMS theoretical m/z=481.3. [M+H]+, found 481.3.

Example 92, Compound 75

N-(2,3-dihydro-1H-indene-2-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 2,3-dihydro-1H-indene-2-carboxylic acid. LCMS theoretical m/z=478.3. [M+H]+, found 478.1.

Example 93, Compound 76

N-(3-cyano-2,2-dimethylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 3-cyano-2,2-dimethylpropanoic acid. LCMS theoretical m/z=443.3. [M+H]+, found 443.1.

Example 94, Compound 77

N-pivaloyl-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with pivalic acid. LCMS theoretical m/z=418.3. [M+H]+, found 418.4.

Example 95, Compound 78

N-(2,3-dihydro-1H-indene-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 2,3-dihydro-1H-indene-1-carboxylic acid, and General Procedure N followed by separation of the diastereomers by chiral SFC to afford title compound as the first eluting isomer as a single enantiomer. LCMS theoretical m/z=478.3. [M+H]+, found 478.2.

Example 96, Compound 78

N-(2,3-dihydro-1H-indene-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer G1 was employed in General Scheme G-2 using General Procedure I with 2,3-dihydro-1H-indene-1-carboxylic acid, and General Procedure N followed by separation of the diastereomers by chiral SFC to afford title compound as the second eluting isomer as a single enantiomer. LCMS theoretical m/z=478.3. [M+H]+, found 478.2.

Example 97, Compound 66

N-(1-phenylcyclopropane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-phenylcyclopropane-1-carboxylic acid. LCMS theoretical m/z=478.3. [M+H]+, found 478.3.

Example 98, Compound 67

N-(2-methyl-2-phenylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-methyl-2-phenylpropanoic acid. LCMS theoretical m/z=480.3. [M+H]+, found 480.3.

Example 99, Compound 68

N-(1-phenylcyclobutane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-phenylcyclobutane-1-carboxylic acid. LCMS theoretical m/z=492.3. [M+H]+, found 492.3.

Example 100, Compound 69

N-(2,2-dimethyl-3-phenylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2,2-dimethyl-3-phenylpropanoic acid. LCMS theoretical m/z=494.3. [M+H]+, found 494.4.

Example 101, Compound 19

N-(tert-butoxycarbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was used in General Procedure N. LCMS theoretical m/z=434.3. [M+H]+, found 434.2.

Example 102, Compound 70

N-(2-(4-fluorophenyl)-2-methylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-(4-fluorophenyl)-2-methylpropanoic acid. LCMS theoretical m/z=498.3. [M+H]+, found 498.3.

Example 103, Compound 71

N-(3-methyloxetane-3-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-methyloxetane-3-carboxylic acid. LCMS theoretical m/z=432.2. [M+H]+, found 432.2.

Example 104, Compound 72

N-(3-hydroxy-2,2-dimethylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-hydroxy-2,2-dimethylpropanoic acid. LCMS theoretical m/z=434.3. [M+H]+, found 434.4.

Example 105, Compound 73

N-(3-methoxy-2,2-dimethylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-methoxy-2,2-dimethylpropanoic acid. LCMS theoretical m/z=448.3. [M+H]+, found 448.4.

Example 106, Compound 74

N-(2-methyl-2-(pyridin-3-yl)propanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-methyl-2-(pyridin-3-yl)propanoic acid. LCMS theoretical m/z=481.3. [M+H]+, found 481.4.

Example 107, Compound 75

N-(2,3-dihydro-1H-indene-2-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2,3-dihydro-1H-indene-2-carboxylic acid. LCMS theoretical m/z=478.3. [M+H]+, found 478.4.

Example 108, Compound 76

N-(3-cyano-2,2-dimethylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-cyano-2,2-dimethylpropanoic acid. LCMS theoretical m/z=443.3. [M+H]+, found 443.3.

Example 109, Compound 77

N-pivaloyl-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared using General Scheme D-2 beginning with Isomer D2 using General Procedure I with pivalic acid. LCMS theoretical m/z=418.3. [M+H]+, found 418.3.

Example 110, Compound 78

N-(2,3-dihydro-1H-indene-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2,3-dihydro-1H-indene-1-carboxylic acid, and General Procedure N to afford the title compound as the first eluting isomer as a single enantiomer. LCMS theoretical m/z=478.3. [M+H]+, found 478.3.

Example 111, Compound 78

N-(2,3-dihydro-1H-indene-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2,3-dihydro-1H-indene-1-carboxylic acid, and General Procedure N to afford the title compound as the second eluting isomer as a single enantiomer. LCMS theoretical m/z=478.3. [M+H]+, found 478.2.

Example 112, Compound 79

N-((neopentyloxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure F with neopentyl chloroformate. LCMS theoretical m/z=448.3. [M+H]+, found 448.3.

Example 113, Compound 80

N-((1-methylcyclopropoxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure J with 1-methylcyclopropan-1-ol, General Procedure K, and General Procedure N. LCMS theoretical m/z=432.3. [M+H]+, found 432.2.

Example 114, Compound 81

N-((1-methylcyclobutoxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure J with 1-methylcyclobutan-1-ol, General Procedure K, and General Procedure N. LCMS theoretical m/z=446.3. [M+H]+, found 446.3.

Example 115, Compound 82

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(((1,1,1-trifluoro-2-methylpropan-2-yl)oxy)carbonyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure J with 1,1,1-trifluoro-2-methylpropan-2-ol, General Procedure K, and General Procedure N. LCMS theoretical m/z=488.2. [M+H]+, found 488.2.

Example 116, Compound 83

N-(isopropoxycarbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure F with isopropyl chloroformate. LCMS theoretical m/z=420.3. [M+H]+, found 420.2.

Example 117, Compound 84

N-(diethylcarbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure H with diethylcarbamoyl chloride. LCMS theoretical m/z=433.3. [M+H]+, found 433.3.

Example 118, Compound 85

N-(tert-butylcarbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure G with tert-butylamine, and General Procedure N. LCMS theoretical m/z=433.3. [M+H]+, found 433.3.

Example 119, Compound 86

N-(tert-butyl(methyl)carbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure G with N,2-dimethylpropan-2-amine, and General Procedure N. LCMS theoretical m/z=447.3. [M+H]+, found 447.3.

Example 120, Compound 87

N-(isopropyl(methyl)carbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure G with N-methylpropan-2-amine, and General Procedure N. LCMS theoretical m/z=433.3. [M+H]+, found 433.3.

Example 121, Compound 88

N-(diisopropylcarbamoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure G with diisopropylamine, and General Procedure N. LCMS theoretical m/z=461.3. [M+H]+, found 461.3.

Example 122, Compound 89

N-(3,3-dimethylbutanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3,3-dimethylbutanoic acid. LCMS theoretical m/z=432.3. [M+H]+, found 432.3.

Example 123, Compound 90

N-(3-methylbutanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-methylbutanoic acid. LCMS theoretical m/z=418.3. [M+H]+, found 418.3.

Example 124, Compound 91

N-(2-cyclobutylacetyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-cyclobutylacetic acid. LCMS theoretical m/z=430.3. [M+H]+, found 430.3.

Example 125, Compound 92

N-(2-(1-methylcyclopropyl)acetyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-(1-methylcyclopropyl)acetic acid. LCMS theoretical m/z=430.3. [M+H]+, found 430.3.

Example 126, Compound 93

N-(2-cyclopropylacetyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-cyclopropylacetic acid. LCMS theoretical m/z=416.3. [M+H]+, found 416.3.

Example 127, Compound 94

N-(((1-(tert-butoxycarbonyl)-3-methylazetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-3-methylazetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-hydroxy-3-methylazetidine-1-carboxylate), and General Procedure N. LCMS theoretical m/z=547.31. [M+H]+, found 547.3.

Example 128, Compound 95

N-(((3-methyl-1-(methylsulfonyl)azetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-3-methylazetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-hydroxy-3-methylazetidine-1-carboxylate), General Procedure D, General Procedure M, then General Procedure N. LCMS theoretical m/z=525.24. [M+H]+, found 525.2.

Example 129, Compound 96

N-(((1-acetyl-3-methylazetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-3-methylazetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-hydroxy-3-methylazetidine-1-carboxylate), General Procedure D, General Procedure L, then General Procedure N. LCMS theoretical m/z=489.27. [M+H]+, found 489.3.

Example 130, Compound 97

N-(((3-methylazetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-3-methylazetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-hydroxy-3-methylazetidine-1-carboxylate), General Procedure D, then General Procedure N. LCMS theoretical m/z=447.26. [M+H]+, found 447.3.

Example 131, Compound 98

N-((cyclohexyloxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure F with cyclohexyl chloroformate. LCMS theoretical m/z=460.28. [M+H]+, found 460.3.

Example 132, Compound 99

N-(isobutoxycarbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure F with isobutyl chloroformate. LCMS theoretical m/z=434.27. [M+H]+, found 434.3.

Example 133, Compound 100

N—((((S)-1-(tert-butoxycarbonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (S)-3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)pyrrolidine-1-carboxylate (prepared using General Procedure J with tert-butyl (S)-3-hydroxypyrrolidine-1-carboxylate), then General Procedure N. LCMS theoretical m/z=547.31. [M+H]+, found 547.3.

Example 134, Compound 101

N—((((S)-pyrrolidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (S)-3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)pyrrolidine-1-carboxylate (prepared using General Procedure J with tert-butyl (S)-3-hydroxypyrrolidine-1-carboxylate), General Procedure D, then General Procedure N. LCMS theoretical m/z=447.26. [M+H]+, found 447.3.

Example 135, Compound 102

N-(4-(methylsulfonyl)butanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-(methylsulfonyl)butanoic acid. LCMS theoretical m/z=482.23. [M+H]+, found 482.2.

Example 136, Compound 103

N—((((S)-1-(methylsulfonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (S)-3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)pyrrolidine-1-carboxylate (prepared using General Procedure J with tert-butyl (S)-3-hydroxypyrrolidine-1-carboxylate), General Procedure D, General Procedure M, then General Procedure N. LCMS theoretical m/z=525.24. [M+H]+, found 525.2.

Example 137, Compound 104

N—((((S)-1-acetylpyrrolidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (S)-3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)pyrrolidine-1-carboxylate (prepared using General Procedure J with tert-butyl (S)-3-hydroxypyrrolidine-1-carboxylate), General Procedure D, General Procedure L, then General Procedure N. LCMS theoretical m/z=489.27. [M+H]+, found 489.3.

Example 138, Compound 100

N—((((R)-1-(tert-butoxycarbonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (R)-3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)pyrrolidine-1-carboxylate (prepared using General Procedure J with tert-butyl (R)-3-hydroxypyrrolidine-1-carboxylate), then General Procedure N. LCMS theoretical m/z=547.31. [M+H]+, found 547.3.

Example 139, Compound 104

N—((((R)-1-acetylpyrrolidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (R)-3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)pyrrolidine-1-carboxylate (prepared using General Procedure J with tert-butyl (R)-3-hydroxypyrrolidine-1-carboxylate), General Procedure D, General Procedure L, then General Procedure N. LCMS theoretical m/z=489.27. [M+H]+, found 489.3.

Example 140, Compound 105

N—(((R)-1-phenylethoxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure K with (R)-2,5-dioxopyrrolidin-1-yl (1-phenylethyl) carbonate (prepared using General Procedure J with (R)-1-phenylethan-1-ol). LCMS theoretical m/z=482.27. [M+H]+, found 482.3.

Example 141, Compound 105

N—(((S)-1-phenylethoxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure K with (S)-2,5-dioxopyrrolidin-1-yl (1-phenylethyl) carbonate (prepared using General Procedure J with (S)-1-phenylethan-1-ol). LCMS theoretical m/z=482.27. [M+H]+, found 482.3.

Example 142, Compound 106

N-((2-phenylcyclobutoxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure K with 2,5-dioxopyrrolidin-1-yl (2-phenylcyclobutyl) carbonate (prepared using General Procedure J with 2-phenylcyclobutan-1-ol). LCMS theoretical m/z=508.28. [M+H]+, found 508.3.

Example 143, Compound 107

N-((cis-3-phenylcyclobutoxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure K with 2,5-dioxopyrrolidin-1-yl ((1s,3 s)-3-phenylcyclobutyl) carbonate (prepared using General Procedure J with (1s,3s)-3-phenylcyclobutan-1-ol). LCMS theoretical m/z=508.28. [M+H]+, found 508.3.

Example 144, Compound 108

N-((((1R,2S)-2-phenylcyclohexyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure K with 2,5-dioxopyrrolidin-1-yl ((1R,2S)-2-phenylcyclohexyl) carbonate (prepared using General Procedure J with (1R,2S)-2-phenylcyclohexan-1-ol). LCMS theoretical m/z=536.31. [M+H]+, found 536.3.

Example 145, Compound 109 Synthesis of trans-2-((tert-butoxycarbonyl)amino)-3-methyl-4-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic acid and cis-2-((tert-butoxycarbonyl)amino)-3-methyl-4-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic Acid (Racemate)

2-(2-((1r,3s)-3-((2-methylallyl)oxy)cyclobutyl)ethyl)-1,8-naphthyridine

To a suspension of sodium hydride (60 wt % dispersion in mineral oil, 64 mg, 1.59 mmol) in DMF (3 mL) at 0° C. was added (1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutan-1-ol (302 mg, 1.32 mmol) in DMF (2 mL) and the resulting mixture was allowed to warm to room temperature and stirred for an additional 30 minutes. To this was then added 3-bromo-2-methylprop-1-ene (357 mg, 2.65 mmol) and the reaction mixture was stirred for 4 hours at room temperature and then diluted with sat. aq. NaHCO₃ and extracted with EtOAc. The combined organic extracts were dried over Na₂SO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give 2-(2-((1r,3s)-3-((2-methylallyl)oxy)cyclobutyl)ethyl)-1,8-naphthyridine.

1-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)propan-2-one

To a mixture of 2-(2-((1r,3 s)-3-((2-methylallyl)oxy)cyclobutyl)ethyl)-1,8-naphthyridine (174 mg, 0.62 mmol) in 3:1 Dioxane/H₂O (3 mL) was added 2,6-lutidine (132 mg, 1.23 mmol), NaIO4 (527 mg, 2.46 mmol), then K₂OsO4.2H₂O (11 mg, 0.03 mmol) and the resulting mixture was allowed to stir at room temperature for 3 hours. The mixture was filtered and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give 1-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)propan-2-one.

methyl 4-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)-3-methylbut-2-enoate

To a solution of 1-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)propan-2-one (175 mg, 0.62 mmol) in CH₂Cl₂ (2 mL) was added methyl 2-((tert-butoxycarbonyl)amino)-2-(dimethoxyphosphoryl)acetate (366 mg, 1.23 mmol) then 1,1,3,3-tetramethylguanidine (142 mg, 1.23 mmol) and the resulting mixture was heated to 40° C. for 2 days. The reaction mixture was cooled to room temperature and then concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give methyl 4-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)-3-methylbut-2-enoate.

methyl 2-((tert-butoxycarbonyl)amino)-3-methyl-4-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoate

To a flask containing methyl 4-((1s,3r)-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)-2-((tert-butoxycarbonyl)amino)-3-methylbut-2-enoate (148 mg, 0.32 mmol) was charged Pd(OH)₂/C (20 wt % on carbon, 30 mg) and the mixture was evacuated and backfilled with H₂ gas for 3 cycles and then stirred under an H₂ atmosphere overnight. The mixture was filtered through a pad of Celite and then concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give methyl 2-((tert-butoxycarbonyl)amino)-3-methyl-4-((1 s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoate.

Example 145a, Compound 109

2-((tert-butoxycarbonyl)amino)-3-methyl-4-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic Acid

Prepared beginning with methyl 2-((tert-butoxycarbonyl)amino)-3-methyl-4-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoate then using General Procedure N whereby a racemic mixture of the title compound was isolated as the second eluting isomer by reverse phase preparative HPLC. LCMS theoretical m/z=448.28. [M+H]+, found 448.3. The absolute stereochemistry of the product of Example 145a was subsequently assigned as (2S,3 S)-2-((tert-butoxycarbonyl)amino)-3-methyl-4-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic acid.

Example 145b, Compound 109

2-((tert-butoxycarbonyl)amino)-3-methyl-4-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic Acid

Prepared beginning with methyl 2-((tert-butoxycarbonyl)amino)-3-methyl-4-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoate then using General Procedure N whereby a racemic mixture of the title compound was isolated as the first eluting peak by reverse phase preparative HPLC. LCMS theoretical m/z=448.28. [M+H]+, found 448.3. The absolute stereochemistry of the product of Example 145b was subsequently assigned as (2S,3R)-2-((tert-butoxycarbonyl)amino)-3-methyl-4-((1 s,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic acid (see structure in FIG. 1, Table 2).

Example 146, Compound 108

N-((((1S,2R)-2-phenylcyclohexyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure K with 2,5-dioxopyrrolidin-1-yl ((1S,2R)-2-phenylcyclohexyl) carbonate (prepared using General Procedure J with (1 S,2R)-2-phenylcyclohexan-1-ol). LCMS theoretical m/z=536.31. [M+H]+, found 536.3.

Example 147, Compound 110

N-(((1-(tert-butoxycarbonyl)azetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)azetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-hydroxyazetidine-1-carboxylate), then General Procedure N. LCMS theoretical m/z=533.30. [M+H]+, found 533.3.

Example 148, Compound 111

N-(((trans-4-phenylcyclohexyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure K with 2,5-dioxopyrrolidin-1-yl (trans-4-phenylcyclohexyl) carbonate (prepared using General Procedure J with trans-4-phenylcyclohexan-1-ol). LCMS theoretical m/z=536.31. [M+H]+, found 536.3.

Example 149, Compound 111

N-(((cis-4-phenylcyclohexyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure K with 2,5-dioxopyrrolidin-1-yl (cis-4-phenylcyclohexyl) carbonate (prepared using General Procedure J with cis-4-phenylcyclohexan-1-ol). LCMS theoretical m/z=536.31. [M+H]+, found 536.3.

Example 150, Compound 112

N-(((1-acetylazetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)azetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-hydroxyazetidine-1-carboxylate), General Procedure D, General Procedure L, then General Procedure N. LCMS theoretical m/z=475.26. [M+H]+, found 475.3.

Example 151, Compound 113

N—((((S)-1-acetamidopropan-2-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (S)-(2-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)propyl)carbamate (prepared using General Procedure J with tert-butyl (S)-(2-hydroxypropyl)carbamate), General Procedure D, General Procedure L, then General Procedure N. LCMS theoretical m/z=477.27. [M+H]+, found 477.3.

Example 152, Compound 114

N—((((S)-1-((tert-butoxycarbonyl)amino)propan-2-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (S)-(2-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)propyl)carbamate (prepared using General Procedure J with tert-butyl (S)-(2-hydroxypropyl)carbamate), then General Procedure N. LCMS theoretical m/z=535.31. [M+H]+, found 535.3.

Example 153

N—((((R)-1-((tert-butoxycarbonyl)amino)propan-2-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (R)-(2-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)propyl)carbamate (prepared using General Procedure J with tert-butyl (R)-(2-hydroxypropyl)carbamate), then General Procedure N. LCMS theoretical m/z=535.31. [M+H]+, found 535.3.

Example 154, Compound 113

N—((((R)-1-acetamidopropan-2-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl (R)-(2-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)propyl)carbamate (prepared using General Procedure J with tert-butyl (R)-(2-hydroxypropyl)carbamate), General Procedure D, General Procedure L, then General Procedure N. LCMS theoretical m/z=477.27. [M+H]+, found 447.3.

Example 155a, Compound 115

N-((((trans)-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl (2,5-dioxopyrrolidin-1-yl) carbonate (racemic, prepared using General Procedure J with trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentan-1-ol), then General Procedure N followed by preparative HPLC to afford the title compound as the first eluting isomer of unknown absolute stereochemistry at the cyclopentane. LCMS theoretical m/z=540.32. [M+H]+, found 540.3. The absolute stereochemistry of the product of Example 155a was subsequently assigned as N-((((1R,2R)-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl)oxy) carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 155b, Compound 115

N-((((trans)-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl (2,5-dioxopyrrolidin-1-yl) carbonate (racemic, prepared using General Procedure J with trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentan-1-ol), then General Procedure N followed by preparative HPLC to afford the title compound as the second eluting isomer of unknown absolute stereochemistry at the cyclopentane. LCMS theoretical m/z=540.32. [M+H]+, found 540.3. The absolute stereochemistry of the product of Example 155b was subsequently assigned as N-((((1S,2S)-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl)oxy) carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 156a, Compound 116

N-((((trans)-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl (2,5-dioxopyrrolidin-1-yl) carbonate (racemic, prepared using General Procedure J with trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexan-1-ol), then General Procedure N followed by preparative HPLC to afford the title compound as the first eluting isomer of unknown absolute stereochemistry at the cyclohexane. LCMS theoretical m/z=554.33. [M+H]+, found 554.4. The absolute stereochemistry of the product of Example 156a was subsequently assigned as N-((((1R,2R)-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl)oxy)carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 156b, Compound 116

N-((((trans)-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl (2,5-dioxopyrrolidin-1-yl) carbonate (racemic, prepared using General Procedure J with trans-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexan-1-ol), then General Procedure N followed by preparative HPLC to afford the title compound as the second eluting isomer of unknown absolute stereochemistry at the cyclohexane. LCMS theoretical m/z=554.33. [M+H]+, found 554.4. The absolute stereochemistry of the product of Example 156b was subsequently assigned as N-((((1 S,2 S)-2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl)oxy)carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 157, Compound 117

N-(((1-(tert-butoxycarbonyl)-3-(3-chlorophenyl)azetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-(3-chlorophenyl)-3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)azetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-(3-chlorophenyl)-3-hydroxyazetidine-1-carboxylate), then General Procedure N. LCMS theoretical m/z=643.29. [M+H]+, found 643.3.

Example 158, Compound 118

N-(((1-(tert-butoxycarbonyl)-3-(4-isopropylphenyl)azetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-3-(4-isopropylphenyl)azetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-hydroxy-3-(4-isopropylphenyl)azetidine-1-carboxylate), then General Procedure N. LCMS theoretical m/z=651.38. [M+H]+, found 651.4.

Example 159, Compound 119

N-(((1-(tert-butoxycarbonyl)-3-(phenylethynyl)azetidin-3-yl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with tert-butyl 3-((((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)oxy)-3-(phenylethynyl)azetidine-1-carboxylate (prepared using General Procedure J with tert-butyl 3-hydroxy-3-(phenylethynyl)azetidine-1-carboxylate), then General Procedure N. LCMS theoretical m/z=633.33. [M+H]+, found 633.4.

Example 160, Compound 120

N-(1-(tert-butoxycarbonyl)piperidine-4-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(tert-butoxycarbonyl)piperidine-4-carboxylic acid. LCMS theoretical m/z=545.33. [M+H]+, found 545.3.

Example 161, Compound 121

N-(3,3-difluorocyclohexane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3,3-difluorocyclohexane-1-carboxylic acid. LCMS theoretical m/z=480.27. [M+H]+, found 480.3.

Example 162a, Compound 122

N-(-2-ethyl-4,4-difluorobutanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-ethyl-4,4-difluorobutanoic acid, then General Procedure N followed by preparative HPLC to afford the title compound as the first eluting isomer of unknown absolute stereochemistry at the 2-ethyl-4,4-difluorobutanoic amide. LCMS theoretical m/z=468.27. [M+H]+, found 468.3. The absolute stereochemistry of the product of Example 162a was subsequently assigned as N—((S)-2-ethyl-4,4-difluorobutanoyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 162b, Compound 122

N-(-2-ethyl-4,4-difluorobutanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-ethyl-4,4-difluorobutanoic acid, then General Procedure N followed by preparative HPLC to afford the title compound as the second eluting isomer of unknown absolute stereochemistry at the 2-ethyl-4,4-difluorobutanoic amide. LCMS theoretical m/z=468.27. [M+H]+, found 468.3. The absolute stereochemistry of the product of Example 162a was subsequently assigned as N—((R)-2-ethyl-4,4-difluorobutanoyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 163a, Compound 123

N-(((trans-2-(phenylethynyl)cyclohexyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with 2,5-dioxopyrrolidin-1-yl trans-2-(phenylethynyl)cyclohexyl) carbonate (prepared using General Procedure J with trans-2-(phenylethynyl)cyclohexan-1-ol), and General Procedure N followed by preparative HPLC to afford the title compound as the first eluting isomer of unknown absolute stereochemistry at the cyclohexane. LCMS theoretical m/z=560.31. [M+H]+, found 560.3. The absolute stereochemistry of the product of Example 163a was subsequently assigned as N-((((1R,2S)-2-(phenylethynyl)cyclohexyl)oxy)carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

N-(((trans-2-(phenylethynyl)cyclohexyl)oxy)carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was sequentially used in General Procedure D, General Procedure K with 2,5-dioxopyrrolidin-1-yl trans-2-(phenylethynyl)cyclohexyl) carbonate (prepared using General Procedure J with trans-2-(phenylethynyl)cyclohexan-1-ol), then General Procedure N followed by preparative HPLC to afford the title compound as the second eluting isomer of unknown absolute stereochemistry at the cyclohexane. LCMS theoretical m/z=560.31. [M+H]+, found 560.3. The absolute stereochemistry of the product of Example 163b was subsequently assigned as N-((((1 S,2R)-2-(phenylethynyl)cyclohexyl)oxy)carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 164, Compound 124

N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-methyltetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=460.28. [M+H]+, found 460.3.

Example 165, Compound 125

N-(2-cyclohexyl-2-methylpropanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-cyclohexyl-2-methylpropanoic acid. LCMS theoretical m/z=486.33. [M+H]+, found 486.3.

Example 166, Compound 126

N-(2-(pyridin-2-yl)benzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-(pyridin-2-yl)benzoic acid. LCMS theoretical m/z=515.27. [M+H]+, found 515.3.

Example 167, Compound 127

N-(2-ethyl-4,4,4-trifluorobutanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-ethyl-4,4,4-trifluorobutanoic acid. LCMS theoretical m/z=486.26. [M+H]+, found 486.3.

Example 168, Compound 128

N-(2-morpholinobenzoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-morpholinobenzoic acid. LCMS theoretical m/z=523.29. [M+H]+, found 523.3.

Example 169, Compound 129

N-(2-ethyl-2-phenylbutanoyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-ethyl-2-phenylbutanoic acid. LCMS theoretical m/z=508.32. [M+H]+, found 508.3.

Example 170, Compound 130

N-(1H-pyrrolo[3,2-b]pyridine-7-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid. LCMS theoretical m/z=478.25. [M+H]+, found 478.4.

Example 171, Compound 131

N-(4-cyanotetrahydro-2H-pyran-4-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-cyanotetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=471.26. [M+H]+, found 471.3.

Example 172, Compound 132

N-(1-(tert-butoxycarbonyl)-3-methylazetidine-3-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(tert-butoxycarbonyl)-3-methylazetidine-3-carboxylic acid. LCMS theoretical m/z=531.32. [M+H]+, found 531.3.

Example 173, Compound 133

N-(1-(tert-butoxycarbonyl)azetidine-3-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(tert-butoxycarbonyl)azetidine-3-carboxylic acid. LCMS theoretical m/z=517.30. [M+H]+, found 517.3.

Example 174, Compound 134

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-(trifluoromethyl)tetrahydro-2H-pyran-4-carboxylic acid, then General Procedure N. LCMS theoretical m/z=514.25. [M+H]+, found 514.3.

Example 175a, Compound 135

N-(1-(methylsulfonyl)piperidine-3-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(methylsulfonyl)piperidine-3-carboxylic acid, then General Procedure N followed by preparative HPLC to afford the title compound as the first eluting isomer of unknown absolute stereochemistry at the piperidine. LCMS theoretical m/z=523.26. [M+H]+, found 523.3. The absolute stereochemistry of the product of Example 175a was subsequently assigned as N—((R)-1-(methylsulfonyl)piperidine-3-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 175b, Compound 135

N-(1-(methylsulfonyl)piperidine-3-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(methylsulfonyl)piperidine-3-carboxylic acid, then General Procedure N followed by preparative HPLC to afford the title compound as the second eluting isomer of unknown absolute stereochemistry at the piperidine. LCMS theoretical m/z=523.26. [M+H]+, found 523.3. The absolute stereochemistry of the product of Example 175b was subsequently assigned as N—((S)-1-(methylsulfonyl)piperidine-3-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 176a, Compound 136

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4,5,6,7-tetrahydro-1H-indazole-6-carboxylic acid, then General Procedure N followed by preparative HPLC to afford the title compound as the first eluting isomer of unknown absolute stereochemistry at the cyclohexylpyrazole. LCMS theoretical m/z=482.28. [M+H]+, found 482.3. The absolute stereochemistry of the product of Example 176a was subsequently assigned as O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N—((R)-4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 176b, Compound 136

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4,5,6,7-tetrahydro-1H-indazole-6-carboxylic acid, then General Procedure N followed by preparative HPLC to separate the diastereomers as the second eluting isomer of unknown absolute stereochemistry at the cyclohexylpyrazole. LCMS theoretical m/z=482.28. [M+H]+, found 482.3. The absolute stereochemistry of the product of Example 176b was subsequently assigned as O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N—((S)-4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 177, Compound 137

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-7-carbonyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4,5,6,7-tetrahydro-1H-indazole-7-carboxylic acid. LCMS theoretical m/z=482.28. [M+H]+, found 482.3.

Example 178, Compound 124

N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme B using General Procedure I with 4-methyltetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=460.28. [M+H]+, found 460.3.

Example 179, Compound 124

N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl) homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-methyltetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=460.3 [M+H]+, found 460.3.

Example 180a, Compound 138

N—((R)-1-methyl-4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-methyl-4,5,6,7-tetrahydro-1H-indazole-6-carboxylic acid, then General Procedure N followed by preparative HPLC to afford the first eluting of two diastereomers as a single stereoisomer. LCMS theoretical m/z=496.29. [M+H]+, found 496.3. The absolute stereochemistry of the product of Example 180a was subsequently assigned as N—((R)-1-methyl-4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 180b, Compound 138

N—((S)-1-methyl-4,5,6,7-tetrahydro-H-indazole-6-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-methyl-4,5,6,7-tetrahydro-1H-indazole-6-carboxylic acid, then General Procedure N followed by preparative HPLC to afford the second eluting of two diastereomers as a single stereoisomer. LCMS theoretical m/z=496.29. [M+H]+, found 496.3. The absolute stereochemistry of the product of Example 180b was subsequently assigned as N—((S)-1-methyl-4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-O-((1s,3 S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine (see structure in FIG. 1, Table 2).

Example 181, Compound 139

N-(1-ethyl-4,4-difluorocyclohexane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-ethyl-4,4-difluorocyclohexane-1-carboxylic acid. LCMS theoretical m/z=508.3. [M+H]+, found 508.3.

Example 182, Compound 140

N-(1-(6-methylindoline-1-carbonyl)cyclopropane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(6-methylindoline-1-carbonyl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=561.3. [M+H]+, found 561.3.

Example 183, Compound 134

O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-trifluoromethyltetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=514.2 [M+H]+, found 514.2.

Example 184, Compound 141

N-(4-(((tert-butoxycarbonyl)amino)methyl)tetrahydro-2H-pyran-4-carbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-(((tert-butoxycarbonyl)amino)methyl)tetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=575.3 [M+H]+, found 575.3.

Example 185, Compound 142

N-(1-(pyridin-3-ylmethyl)cyclopropane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(pyridin-3-ylmethyl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=493.3. [M+H]+, found 493.2.

Example 186, Compound 143

N-(3-chloro-5-methylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 3-chloro-5-methylisonicotinic acid. LCMS theoretical m/z=461.2 [M+H]+, found 461.2.

Example 187, Compound 144

N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 4-methyltetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=434.3 [M+H]+, found 434.3.

Example 188, Compound 145

N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 2,6-dichlorobenzoic acid. LCMS theoretical m/z=480.1 [M+H]+, found 480.2.

Example 189, Compound 146

N-(3,5-dichloroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme C using General Procedure I with 3,5-dichloroisonicotinic acid. LCMS theoretical m/z=481.1 [M+H]+, found 481.2.

Example 190, Compound 147

N-(1-(4-(tert-butyl)phenyl)cyclobutane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(4-(tert-butyl)phenyl)cyclobutane-1-carboxylic acid. LCMS theoretical m/z=548.3. [M+H]+, found 548.3.

Example 191, Compound 124

N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E1 was employed in General Scheme E-2 using General Procedure I with 4-methyltetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=460.3. [M+H]+, found 460.3.

Example 192, Compound 134

O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserine

Isomer E1 was employed in General Scheme E-2 using General Procedure I with 4-(trifluoromethyl)tetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=514.3. [M+H]+, found 514.3.

Example 193, Compound 148

N-(3,5-dimethylisonicotinoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E1 was employed in General Scheme E-2 using General Procedure I with 3,5-dimethylisonicotinic acid. LCMS theoretical m/z=467.3. [M+H]+, found 467.3.

Example 194, Compound 149

N-(3-chloro-5-methylisonicotinoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E1 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-methylisonicotinic acid. LCMS theoretical m/z=487.2 [M+H]+, found 487.2.

Example 195, Compound 150

N-(3,5-dichloroisonicotinoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3,5-dichloroisonicotinic acid. LCMS theoretical m/z=507.1 [M+H]+, found 507.1.

Example 196, Compound 151

N-(bicyclo[2.2.2]octane-2-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with bicyclo[2.2.2]octane-2-carboxylic acid. LCMS theoretical m/z=470.3. [M+H]+, found 470.3.

Example 197, Compound 152

N-(2-methyl-1,2,3,4-tetrahydronaphthalene-2-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-methyl-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid. LCMS theoretical m/z=430.27. [M+H]+, found 430.3.

Example 198, Compound 153

N-((methylsulfonyl)prolyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with (methylsulfonyl)proline. LCMS theoretical m/z=509.2. [M+H]+, found 509.3.

Example 199, Compound 149

N-(3-chloro-5-methylisonicotinoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-methylisonicotinic acid. LCMS theoretical m/z=487.2 [M+H]+, found 487.2.

Example 200, Compound 154

N-(2,4-dimethylnicotinoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,4-dimethylnicotinic acid. LCMS theoretical m/z=467.3 [M+H]+, found 467.3.

Example 201, Compound 155

N-(4-phenyltetrahydro-2H-pyran-4-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-phenyltetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=522.3. [M+H]+, found 522.2.

Example 202, Compound 156

N-(4-cyano-2,6-dimethylbenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-cyano-2,6-dimethylbenzoic acid. LCMS theoretical m/z=491.3 [M+H]+, found 491.3.

Example 203, Compound 157

O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2,4,6-trimethylpyrimidine-5-carbonyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,4,6-trimethylpyrimidine-5-carboxylic acid. LCMS theoretical m/z=482.3 [M+H]+, found 482.2.

Example 204, Compound 158

O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2,4,6-trimethylnicotinoyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,4,6-trimethylnicotinic acid. LCMS theoretical m/z=481.3 [M+H]+, found 481.2.

Example 205, Compound 159

N-(3-chloro-5-fluoroisonicotinoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-fluoroisonicotinic acid. LCMS theoretical m/z=491.2 [M+H]+, found 491.1.

Example 206, Compound 160

N-(1-(isoquinolin-1-yl)cyclopropane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(isoquinolin-1-yl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=529.3. [M+H]+, found 529.3.

Example 207, Compound 161

N-(2-(pyridin-2-yl)spiro[3.3]heptane-2-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-(pyridin-2-yl)spiro[3.3]heptane-2-carboxylic acid. LCMS theoretical m/z=533.3. [M+H]+, found 533.3.

Example 208, Compound 162

N-(2-(1-methyl-1H-pyrazol-4-yl)tetrahydrofuran-2-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-(1-methyl-1H-pyrazol-4-yl)tetrahydrofuran-2-carboxylic acid, then General Procedure N followed by preparative HPLC to afford the title compound as the first eluting isomer. LCMS theoretical m/z=512.3. [M+H]+, found 512.3.

Example 209, Compound 162

N-(2-(1-methyl-1H-pyrazol-4-yl)tetrahydrofuran-2-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-(1-methyl-1H-pyrazol-4-yl)tetrahydrofuran-2-carboxylic acid, then General Procedure N followed by preparative HPLC to afford the title compound as the second eluting isomer. LCMS theoretical m/z=512.3. [M+H]+, found 512.3.

Example 210, Compound 163

N-(2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid. LCMS theoretical m/z=491.2 [M+H]+, found 491.1.

Example 211, Compound 164

N-(4,6-dimethylpyrimidine-5-carbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4,6-dimethylpyrimidine-5-carboxylic acid. LCMS theoretical m/z=468.3 [M+H]+, found 468.2.

Example 212, Compound 165

N-(2,6-dichloro-4-(trifluoromethyl)benzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,6-dichloro-4-(trifluoromethyl)benzoic acid. LCMS theoretical m/z=574.1 [M+H]+, found 574.1.

Example 213, Compound 166

N-(1-(2-fluorophenyl)cyclopropane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(2-fluorophenyl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=512.3. [M+H]+, found 512.3.

Example 214, Compound 167

N-(1-(benzo[d][1,3]dioxol-5-yl)cyclohexane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(benzo[d][1,3]dioxol-5-yl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=564.3. [M+H]+, found 564.3.

Example 215, Compound 168

N-(2,2-difluoro-1-(m-tolyl)cyclopropane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2,2-difluoro-1-(m-tolyl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=528.3. [M+H]+, found 528.3.

Example 216, Compound 169

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1-(tetrahydro-2H-pyran-2-yl)cyclopropane-1-carbonyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(tetrahydro-2H-pyran-2-yl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=486.3. [M+H]+, found 486.3.

Example 217, Compound 170

N-(4-methoxy-2,6-dimethylbenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-methoxy-2,6-dimethylbenzoic acid. LCMS theoretical m/z=496.3 [M+H]+, found 496.2.

Example 218, Compound 171

N-(1-acetyl-4-(trifluoromethyl)piperidine-4-carbonyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was sequentially used in General Procedure D, General Procedure I with 1-(tert-butoxycarbonyl)-4-(trifluoromethyl)piperidine-4-carboxylic acid, General Procedure D, General Procedure L, and General Procedure N. LCMS theoretical m/z=496.3 [M+H]+, found 496.2.

Example 219, Compound 172

N-(2,3-dihydrobenzo[b][1,4]dioxine-2-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2,3-dihydrobenzo[b][1,4]dioxine-2-carboxylic acid. LCMS theoretical m/z=496.2. [M+H]+, found 496.2.

Example 220, Compound 173

N-(1-(3-chlorobenzyl)cyclopentane-1-carbonyl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(3-chlorobenzyl)cyclopentane-1-carboxylic acid. LCMS theoretical m/z=554.3. [M+H]+, found 554.3.

Example 221, Compound 174

O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1-(3-(trifluoromethoxy)phenyl)cyclopropane-1-carbonyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(3-(trifluoromethoxy)phenyl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=562.2. [M+H]+, found 562.2.

Example 222, Compound 175

N-(4-fluoro-2,6-dimethylbenzoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-fluoro-2,6-dimethylbenzoic acid. LCMS theoretical m/z=484.3 [M+H]+, found 484.2.

Example 223, Compound 148

N-(3,5-dimethylisonicotinoyl)-O-(cis-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3,5-dimethylisonicotinic acid. LCMS theoretical m/z=467.3 [M+H]+, found 467.2.

Example 224, Compound 178

N-(quinazolin-4-yl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Prepared according to General Scheme A using General Procedure E with 4-chloroquinazoline. LCMS theoretical m/z=462.3. [M+H]+, found 462.3.

Example 225, Compound 187

N-(2-(tert-butyl)pyrimidin-4-yl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure E with 2-tert-butyl-4-chloro-pyrimidine. LCMS theoretical m/z=468.3 [M+H]+, found 468.3.

Example 226, Compound 188

N-(4-(tert-butyl)pyrimidin-2-yl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure E with 4-(tert-butyl)-2-chloropyrimidine. LCMS theoretical m/z=468.3 [M+H]+, found 468.3.

Example 227, Compound 178

O-(trans-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(quinazolin-4-yl)homoserine

Isomer D1 was employed in General Scheme D-2 following General Procedure E with 4-chloroquinazoline. LCMS theoretical m/z=462.3 [M+H]+, found 462.3.

Example 228, Compound 178

O-(trans-3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(quinazolin-4-yl)homoserine

Isomer D2 was employed in General Scheme D-2 following General Procedure E with 4-chloroquinazoline. LCMS theoretical m/z=462.3 [M+H]+, found 462.3.

Example 229, Compound 186

N-(6-(tert-butyl)pyrimidin-4-yl)-O-(trans-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure E with 4-(tert-butyl)-6-chloropyrimidine. LCMS theoretical m/z=468.3 [M+H]+, found 468.3.

Example 230, Compound 210

N-(4-amino-2,6-dichlorobenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-amino-2,6-dichlorobenzoic acid. LCMS theoretical m/z=520.2. [M+H]+, found 521.1.

Example 231, Compound 211

N-(4-chloro-2,6-dimethylnicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-chloro-2,6-dimethylnicotinic acid. LCMS theoretical m/z=500.2. [M+H]+, found 501.2.

Example 232, Compound 212

N-(3-chloro-6-methylpicolinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-6-methylpicolinic acid. LCMS theoretical m/z=486.2. [M+H]+, found 487.2.

Example 233, Compound 213

N-((2R,6S)-2,6-dimethylpiperidine-1-carbonyl)-O-((1r,3R)—O-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure G with (2R,6S)-2,6-dimethylpiperidine. LCMS theoretical m/z=472.3. [M+H]+, found 473.3.

Example 234, Compound 214

N-((2R,5S)-2,5-dimethylpyrrolidine-1-carbonyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure G with (2R,5 S)-2,5-dimethylpyrrolidine. LCMS theoretical m/z=458.3. [M+H]+, found 459.3.

Example 235, Compound 215

N-((2R,5R)-2,5-dimethylpyrrolidine-1-carbonyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure G with (2R,5R)-2,5-dimethylpyrrolidine. LCMS theoretical m/z=458.3. [M+H]+, found 459.3.

Example 236, Compound 216

N-(2,6-dichloro-4-cyanobenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,6-dichloro-4-cyanobenzoic acid. LCMS theoretical m/z=530.1. [M+H]+, found 531.1.

Example 237, Compound 217

N-(2,6-dichloro-3-nitrobenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,6-dichloro-3-nitrobenzoic acid. LCMS theoretical m/z=550.2. [M+H]+, found 551.2.

Example 238, Compound 218

O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1,2,4-trimethyl-6-oxo-1,6-dihydropyridine-3-carbonyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 1,2,4-trimethyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid. LCMS theoretical m/z=496.3. [M+H]+, found 497.3.

Example 239, Compound 219

N-(2-chloro-4-cyano-6-methylbenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2-chloro-4-cyano-6-methylbenzoic acid. LCMS theoretical m/z=510.2. [M+H]+, found 511.2.

Example 240, Compound 220

N-(3-bromo-5-chloro-2-fluoroisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-bromo-5-chloro-2-fluoroisonicotinic acid. LCMS theoretical m/z=568.1. [M+H]+, found 569.1.

Example 241, Compound 221

O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(5,6,7,8-tetrahydronaphthalene-1-carbonyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 5,6,7,8-tetrahydronaphthalene-1-carboxylic acid. LCMS theoretical m/z=491.3. [M+H]+, found 492.3.

Example 242, Compound 222

N-(3-bromo-2,6-dimethylbenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-bromo-2,6-dimethylbenzoic acid. LCMS theoretical m/z=543.2. [M+H]+, found 544.2.

Example 243, Compound 223

N-(3-chloro-5-methoxyisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-methoxyisonicotinic acid. LCMS theoretical m/z=502.2. [M+H]+, found 503.2.

Example 244, Compound 224

N-(2,6-dichloro-4-fluorobenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,6-dichloro-4-fluorobenzoic acid. LCMS theoretical m/z=523.1. [M+H]+, found 524.1.

Example 245, Compound 225

N-(2-chloro-6-fluorobenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2-chloro-6-fluorobenzoic acid. LCMS theoretical m/z=489.2. [M+H]+, found 489.9.

Example 246, Compound 226

N-(3-bromo-2-chloro-6-fluorobenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-bromo-2-chloro-6-fluorobenzoic acid. LCMS theoretical m/z=567.1. [M+H]+, found 568.1.

Example 247, Compound 227

N-(2,4-dimethyl-6-oxo-1-phenyl-1,6-dihydropyridine-3-carbonyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,4-dimethyl-6-oxo-1-phenyl-1,6-dihydropyridine-3-carboxylic acid. LCMS theoretical m/z=558.3. [M+H]+, found 559.3.

Example 248, Compound 228

N-(5-bromo-2-hydroxyisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 5-bromo-2-hydroxyisonicotinic acid. LCMS theoretical m/z=532.1. [M+H]+, found 533.1.

Example 249, Compound 229

N-(3-chloro-5-cyclopropylisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-cyclopropylisonicotinic acid. LCMS theoretical m/z=512.2. [M+H]+, found 513.2.

Example 250, Compound 230

N-(3-chloro-5-ethylisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-ethylisonicotinic acid. LCMS theoretical m/z=500.2. [M+H]+, found 501.2.

Example 251, Compound 231

N-(3-chloro-5-ethylisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-cyano-2,6-dimethylbenzoic acid. LCMS theoretical m/z=490.2. [M+H]+, found 491.2.

Example 252, Compound 232

N-(3-bromo-5-fluoroisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-bromo-5-fluoroisonicotinic acid. LCMS theoretical m/z=534.1. [M+H]+, found 535.1.

Example 253, Compound 233

N-(2-methoxy-3,5-dimethylisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2-methoxy-3,5-dimethylisonicotinic acid. LCMS theoretical m/z=496.2. [M+H]+, found 497.2.

Example 254, Compound 234

N-(3-chloro-5-(trifluoromethyl)isonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-(trifluoromethyl)isonicotinic acid. LCMS theoretical m/z=540.2. [M+H]+, found 541.2.

Example 255, Compound 235

N-(3-bromo-5-chloroisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-bromo-5-chloroisonicotinic acid. LCMS theoretical m/z=550.1. [M+H]+, found 551.1.

Example 256, Compound 236

N-(5-chloro-2-(dimethylamino)-3-methylisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 5-chloro-2-(dimethylamino)-3-methylisonicotinic acid. LCMS theoretical m/z=509.3. [M+H]+, found 510.2.

Example 257, Compound 237

N-(3-chloro-5-fluoro-2-methooylsonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-fluoro-2-methylisonicotinic acid. LCMS theoretical m/z=504.2. [M+H]+, found 505.1.

Example 258, Compound 238

N-(2,6-dichloro-3-cyanobenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,6-dichloro-3-cyanobenzoic acid. LCMS theoretical m/z=530.1. [M+H]+, found 531.1.

Example 259, Compound 239

N-(3-methyl-5-(trifluoromethyl)isonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-methyl-5-(trifluoromethyl)isonicotinic acid. LCMS theoretical m/z=520.2. [M+H]+, found 521.2.

Example 260, Compound 240

N-(2-hydroxy-3,5-dimethylisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2-hydroxy-3,5-dimethylisonicotinic acid. LCMS theoretical m/z=488.2. [M+H]+, found 483.2.

Example 261, Compound 241

N-(3-cyano-2-hydroxy-6-methylisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-cyano-2-hydroxy-6-methylisonicotinic acid. LCMS theoretical m/z=493.2. [M+H]+, found 494.2.

Example 262, Compound 242

N-(5-chloro-3-fluoro-2-methylisonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 5-chloro-3-fluoro-2-methylisonicotinic acid. LCMS theoretical m/z=504.2. [M+H]+, found 505.2.

Example 263, Compound 243

N-(6-methoxy-2,4-dimethylnicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 6-methoxy-2,4-dimethylnicotinic acid. LCMS theoretical m/z=496.2. [M+H]+, found 497.2.

Example 264, Compound 244

N-(2,6-dimethyl-4-((4-methylpiperazin-1-yl)methyl)benzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,6-dimethyl-4-((4-methylpiperazin-1-yl)methyl)benzoic acid. LCMS theoretical m/z=577.3. [M+H]+, found 578.3.

Example 265, Compound 245

N-((phenylsulfonyl)-L-prolyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with (phenylsulfonyl)-L-proline. LCMS theoretical m/z=570.2. [M+H]+, found 571.2.

Example 266, Compound 246

N-((3R,5S)-3,5-dimethylmorpholine-4-carbonyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure G with (3R,5S)-3,5-dimethylmorpholine. LCMS theoretical m/z=474.3. [M+H]+, found 475.3.

Example 267, Compound 247

N-(5-chloro-3-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 5-chloro-3-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinic acid. LCMS theoretical m/z=602.3. [M+H]+, found 603.3.

Example 268, Compound 248

N-(7-chloro-5-oxo-1,2,3,5-tetrahydroindolizine-8-carbonyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 7-chloro-5-oxo-1,2,3,5-tetrahydroindolizine-8-carboxylic acid. LCMS theoretical m/z=528.2. [M+H]+, found 529.2.

Example 269, Compound 249

N-(2,6-difluoro-4-hydroxybenzoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2,6-difluoro-4-hydroxybenzoic acid. LCMS theoretical m/z=489.2. [M+H]+, found 490.2.

Example 270, Compound 250

N-(4-chloro-1-methyl-1H-pyrazole-5-carbonyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4-chloro-1-methyl-1H-pyrazole-5-carboxylic acid. LCMS theoretical m/z=475.2. [M+H]+, found 476.2.

Example 271, Compound 251

N-(1-methyl-1H-pyrazole-5-carbonyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 1-methyl-1H-pyrazole-5-carboxylic acid. LCMS theoretical m/z=441.2. [M+H]+, found 442.2.

Example 272, Compound 252

N-(3-chloro-5-fluoroisonicotinoyl)-O-((1r,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-D-homoserine

Isomer E1 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-fluoroisonicotinic acid. LCMS theoretical m/z=490.2. [M+H]+, found 491.2.

Example 273, Compound 253

N—((S)-1-(phenylsulfonyl)piperidine-2-carbonyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with (S)-1-(phenylsulfonyl)piperidine-2-carboxylic acid. LCMS theoretical m/z=584.3. [M+H]+, found 585.2.

Example 274, Compound 254

N-(3-chloro-5-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3-chloro-5-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinic acid. LCMS theoretical m/z=602.3. [M+H]+, found 603.3.

Example 275, Compound 255

N-(3,3-dimethylbutanoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 3,3-dimethylbutanoic acid. LCMS theoretical m/z=431.3. [M+H]+, found 432.3.

Example 276, Compound 256

N-(2-phenylacetyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2-phenylacetic acid. LCMS theoretical m/z=451.3. [M+H]+, found 452.3.

Example 277, Compound 257

O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,4,4-trifluoro-3,3-dimethylbutanoyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4,4,4-trifluoro-3,3-dimethylbutanoic acid. LCMS theoretical m/z=485.3. [M+H]+, found 486.3.

Example 278, Compound 258

N-(4,4-difluoro-3,3-dimethylbutanoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 4,4-difluoro-3,3-dimethylbutanoic acid. LCMS theoretical m/z=467.3. [M+H]+, found 468.3.

Example 279, Compound 259

N—((S)-2-phenylpropanoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with (S)-2-phenylpropanoic acid. LCMS theoretical m/z=465.3. [M+H]+, found 466.3.

Example 280, Compound 260

N-(2-(3,5-difluorophenyl)acetyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure I with 2-(3,5-difluorophenyl)acetic acid. LCMS theoretical m/z=487.2. [M+H]+, found 488.2.

Example 281, Compound 261

N—((((S)-1-((tert-butoxycarbonyl)amino)propan-2-yl)oxy)carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with (S)-1-((tert-butoxycarbonyl)amino)propan-2-yl hydrogen carbonate. LCMS theoretical m/z=534.3. [M+H]+, found 535.3.

Example 282, Compound 262

N-(3,6-dimethylpicolinoyl)-O-((1r,3R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3,6-dimethylpicolinic acid. LCMS theoretical m/z=466.3. [M+H]+, found 467.3.

Example 283, Compound 263

N-(6-fluorochromane-2-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 6-fluorochromane-2-carboxylic acid. LCMS theoretical m/z=511.3. [M+H]+, found 512.3.

Example 284, Compound 264

O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2-(3-(trifluoromethyl)phenyl)butanoyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-(3-(trifluoromethyl)phenyl)butanoic acid. LCMS theoretical m/z=547.3. [M+H]+, found 548.3.

Example 285, Compound 265

N-(3-chloro-5-methylisonicotinoyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-chloro-5-methylisonicotinic acid. LCMS theoretical m/z=486.2. [M+H]+, found 487.2.

Example 286, Compound 266

N-(3-chloro-5-fluoroisonicotinoyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-chloro-5-fluoroisonicotinic acid. LCMS theoretical m/z=490.2. [M+H]+, found 491.2.

Example 287, Compound 267

N-(4-cyano-2,6-dimethylbenzoyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-cyano-2,6-dimethylbenzoic acid. LCMS theoretical m/z=490.3. [M+H]+, found 491.3.

Example 288, Compound 268

N-(4-(2-chlorophenyl)tetrahydro-2H-pyran-4-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-(2-chlorophenyl)tetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=555.3. [M+H]+, found 556.3.

Example 289, Compound 269

N-(2-hydroxy-2,3-dihydro-1H-indene-2-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 2-hydroxy-2,3-dihydro-1H-indene-2-carboxylic acid. LCMS theoretical m/z=493.3. [M+H]+, found 494.2.

Example 290, Compound 270

N-([1,1′-bi(cyclopropane)]-1-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with [1,1′-bi(cyclopropane)]-1-carboxylic acid. LCMS theoretical m/z=441.3. [M+H]+, found 442.3.

Example 291, Compound 271

N—((S)-3-(difluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridine-6-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-(difluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridine-6-carboxylic acid. LCMS theoretical m/z=532.3. [M+H]+, found 533.3.

Example 292, Compound 272

N—((R)-3-(difluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridine-6-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-(difluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridine-6-carboxylic acid. LCMS theoretical m/z=532.3. [M+H]+, found 533.3.

Example 293, Compound 273

N-(1-cyclopropylcyclobutane-1-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-cyclopropylcyclobutane-1-carboxylic acid. LCMS theoretical m/z=455.3. [M+H]+, found 456.3.

Example 294, Compound 274

N-(1-(4-isopropylphenyl)cyclopentane-1-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(4-isopropylphenyl)cyclopentane-1-carboxylic acid. LCMS theoretical m/z=547.3. [M+H]+, found 548.3.

Example 295, Compound 275

N-(bicyclo[2.2.2]octane-1-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with bicyclo[2.2.2]octane-1-carboxylic acid. LCMS theoretical m/z=469.3. [M+H]+, found 470.3.

Example 296, Compound 276

N-(octahydrobenzofuran-3a-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with octahydrobenzofuran-4-carboxylic acid. LCMS theoretical m/z=485.3. [M+H]+, found 486.3.

Example 297, Compound 277

N-(1-phenethylcyclopropane-1-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-phenethylcyclopropane-1-carboxylic acid. LCMS theoretical m/z=505.3. [M+H]+, found 506.3.

Example 298, Compound 278

N-(4-(3-methylisoxazol-5-yl)tetrahydro-2H-pyran-4-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-(3-methylisoxazol-5-yl)tetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=526.3. [M+H]+, found 527.1.

Example 299, Compound 279

N-(1-(phenylsulfonyl)cyclopropane-1-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(phenylsulfonyl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=541.2. [M+H]+, found 542.2.

Example 300, Compound 280

N-(1-phenylcycloheptane-1-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-phenylcycloheptane-1-carboxylic acid. LCMS theoretical m/z=533.3. [M+H]+, found 534.3.

Example 301, Compound 281

N-(4-(methylsulfonyl)tetrahydro-2H-pyran-4-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 4-(methylsulfonyl)tetrahydro-2H-pyran-4-carboxylic acid. LCMS theoretical m/z=523.2. [M+H]+, found 524.2.

Example 302, Compound 282

N-(1-(4-sulfamoylphenyl)cyclopropane-1-carbonyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 1-(4-sulfamoylphenyl)cyclopropane-1-carboxylic acid. LCMS theoretical m/z=556.2. [M+H]+, found 557.2.

Example 303, Compound 283

N-((phenylsulfonyl)-L-prolyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with (phenylsulfonyl)-L-proline. LCMS theoretical m/z=570.2. [M+H]+, found 571.2.

Example 304, Compound 284

N-(5-chloro-3-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinoyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 5-chloro-3-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinic acid. LCMS theoretical m/z=602.3. [M+H]+, found 603.3.

Example 305, Compound 285

N-(3-chloro-5-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinoyl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with 3-chloro-5-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinic acid. LCMS theoretical m/z=602.3. [M+H]+, found 603.3.

Example 306, Compound 286

(S)-2-(pyrimidin-4-ylamino)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic Acid

Prepared by modifying the reaction with intermediate 2i in Example 2 to replace 2-ethylbutanoic acid with 4-chloropyrimidine and sodium bicarbonate. LCMS theoretical m/z=385.2. [M+H]+, found 386.2.

Example 307, Compound 287

N-(3,5-dichloroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-, 8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 3,5-dichloroisonicotinic acid. LCMS theoretical m/z=480.1. [M+H]+, found 481.1.

Example 308, Compound 288

N-(3-chloro-5-methylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 3-chloro-5-methylisonicotinic acid. LCMS theoretical m/z=460.2. [M+H]+, found 461.2.

Example 309, Compound 289

N-(2,4-dimethylnicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 2,4-dimethylnicotinic acid. LCMS theoretical m/z=440.2. [M+H]+, found 441.2.

Example 310, Compound 290

N-(4-cyano-2,6-dimethylbenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 4-cyano-2,6-dimethylbenzoic acid. LCMS theoretical m/z=464.2. [M+H]+, found 465.3.

Example 311, Compound 291

N-(3,5-dichloroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Isomer F1 was employed in General Scheme F-2 using General Procedure I with 3,5-dichloroisonicotinic acid. LCMS theoretical m/z=480.1. [M+H]+, found 481.1.

Example 312, Compound 292

N-(3-chloro-5-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 3-chloro-5-fluoroisonicotinic acid. LCMS theoretical m/z=464.2. [M+H]+, found 465.1.

Example 313, Compound 293

N-((3R,5S)-3,5-dimethylmorpholine-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure G with (3R,5S)-3,5-dimethylmorpholine. LCMS theoretical m/z=448.3. [M+H]+, found 449.3.

Example 314, Compound 294

N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Isomer F1 was employed in General Scheme F-2 using General Procedure I with 2,6-dichlorobenzoic acid. LCMS theoretical m/z=479.1. [M+H]+, found 480.1.

Example 315, Compound 295

N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 2,6-dichlorobenzoic acid. LCMS theoretical m/z=479.1. [M+H]+, found 480.1.

Example 316, Compound 296

N-(3,5-dimethylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Isomer F1 was employed in General Scheme F-2 using General Procedure I with 3,5-dimethylisonicotinic acid. LCMS theoretical m/z=440.2. [M+H]+, found 441.2.

Example 317, Compound 297

N-(3,5-dimethylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 3,5-dimethylisonicotinic acid. LCMS theoretical m/z=440.2. [M+H]+, found 441.2.

Example 318, Compound 298

N-(2,4-dichloro-6-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 2,4-dichloro-6-fluorobenzoic acid. LCMS theoretical m/z=497.1 [M+H]+, found 498.1.

Example 319, Compound 299

N-(2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid. LCMS theoretical m/z=456.2. [M+H]+, found 457.2.

Example 320, Compound 300

N-(3-chloro-5-methoxyisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 3-chloro-5-methoxyisonicotinic acid. LCMS theoretical m/z=476.2. [M+H]+, found 477.1.

Example 321, Compound 301

N-(2-chloro-6-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 2-chloro-6-fluorobenzoic acid. LCMS theoretical m/z=463.2. [M+H]+, found 464.2.

Example 322, Compound 302

N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure N. LCMS theoretical m/z=421.2. [M+H]+, found 422.2.

Example 323, Compound 303

N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Isomer F1 was employed in General Scheme F-2 using General Procedure N. LCMS theoretical m/z=421.2. [M+H]+, found 422.2.

Example 324, Compound 304

N-(5-bromo-2-hydroxyisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 5-bromo-2-hydroxyisonicotinic acid. LCMS theoretical m/z=506.1. [M+H]+, found 507.1.

Example 325, Compound 305

N-(3-bromo-5-chloro-2-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 3-bromo-5-chloro-2-fluoroisonicotinic acid. LCMS theoretical m/z=542.1. [M+H]+, found 543.1.

Example 326, Compound 306

N-(2,4-dimethyl-6-oxo-1-phenyl-1,6-dihydropyridine-3-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 2,4-dimethyl-6-oxo-1-phenyl-1,6-dihydropyridine-3-carboxylic acid. LCMS theoretical m/z=532.3. [M+H]+, found 533.3.

Example 327, Compound 307

O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-N-(5,6,7,8-tetrahydronaphthalene-1-carbonyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 5,6,7,8-tetrahydronaphthalene-1-carboxylic acid. LCMS theoretical m/z=465.3. [M+H]+, found 466.2.

Example 328, Compound 308

N-(3-bromo-2,6-dimethylbenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 3-bromo-2,6-dimethylbenzoic acid. LCMS theoretical m/z=517.2. [M+H]+, found 518.2.

Example 329, Compound 309

N-(3-chloro-5-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Isomer F1 was employed in General Scheme F-2 using General Procedure I with 3-chloro-5-fluoroisonicotinic acid. LCMS theoretical m/z=464.1. [M+H]+, found 465.1.

Example 330, Compound 310

N-(3-bromo-2-chloro-6-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Isomer F2 was employed in General Scheme F-2 using General Procedure I with 3-bromo-2-chloro-6-fluorobenzoic acid. LCMS theoretical m/z=541.1. [M+H]+, found 542.1.

tert-butyl 7-(4-hydroxy-3-methylbutyl)-3,4-dihydro-1,8-naphthyridine-(2H)-carboxylate (2I in Scheme I)

To a solution of tert-butyl 7-(4-ethoxy-4-oxobutyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate (11 in Scheme I, 20 g, 57.40 mmol) and MeI (8.15 g, 57.40 mmol) in THF (200 mL) was added KHMDS (1 M, 57.40 mL) dropwise under N₂ at −78° C. and the resulting mixture was allowed to stir for 1 h at −78° C. The mixture was then warmed to 0° C. and then to this was slowly added EtOAc (100 mL) followed by a saturated aqueous solution of ammonium chloride (600 mL). The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were dried over Na₂SO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give the title compound. Starting from the title compound, the remainder of the reactions in Scheme I were conducted analogously to the corresponding reactions in Scheme C/General Procedure C to provide the following five compounds.

Example 331, Compound 311

N-(3-chloro-5-fluoroisonicotinoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme I using General Procedure N with 3-chloro-5-fluoroisonicotinic acid whereby the title compound was isolated a racemic mixture. LCMS theoretical m/z=478.1. [M+H]+, found 479.1.

Example 332, Compound 312

N-(3-chloro-5-fluoroisonicotinoyl)-O—((R)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme I using General Procedure N with 3-chloro-5-fluoroisonicotinic acid to provide a racemic mixture. The title compound was isolated from the racemic mixture as the fourth eluting isomer by SFC. LCMS theoretical m/z=478.1. [M+H]+, found 479.1.

Example 333, Compound 313

N-(3-chloro-5-fluoroisonicotinoyl)-O—((S)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Prepared according to General Scheme I using General Procedure N with 3-chloro-5-fluoroisonicotinic acid to provide a racemic mixture. The title compound was isolated from the racemic mixture as the first eluting isomer by SFC. LCMS theoretical m/z=478.1. [M+H]+, found 479.1.

Example 334, Compound 314

N-(3-chloro-5-fluoroisonicotinoyl)-O—((R)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Prepared according to General Scheme I using General Procedure N with 3-chloro-5-fluoroisonicotinic acid to provide a racemic mixture. The title compound was isolated from the racemic mixture as the second eluting isomer by SFC. LCMS theoretical m/z=478.1. [M+H]+, found 479.1.

Example 335, Compound 315

N-(3-chloro-5-fluoroisonicotinoyl)-O—((S)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme I using General Procedure N with 3-chloro-5-fluoroisonicotinic acid to provide a racemic mixture. The title compound was isolated from the racemic mixture as the third eluting isomer by SFC. LCMS theoretical m/z=478.1. [M+H]+, found 479.1.

Example 336, Compound 316

N-(3-chloro-5-methoxyisonicotinoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine

Prepared according to General Scheme I using General Procedure N with 3-chloro-5-methoxyisonicotinic acid to provide a racemic mixture. The title compound was isolated from the racemic mixture by preparative reverse phase HPLC. LCMS theoretical m/z=490.2. [M+H]+, found 490.9.

Example 337, Compound 317

N-(2,6-dichlorobenzoyl)-O—((S)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Prepared according to General Scheme I using General Procedure N with 2,6-dichlorobenzoic acid. The title compound was isolated as the first eluting isomer by SFC. LCMS theoretical m/z=493.2. [M+H]+, found 494.2.

Example 338, Compound 318

N-(2,6-dichlorobenzoyl)-O—((R)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Prepared according to General Scheme I using General Procedure N with 2,6-dichlorobenzoic acid. The title compound was isolated as the second eluting isomer by SFC. LCMS theoretical m/z=493.2. [M+H]+, found 494.2.

Example 339, Compound 319

N-(2,6-dichlorobenzoyl)-O—((S)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme I using General Procedure N with 2,6-dichlorobenzoic acid. The title compound was isolated as the third eluting isomer by SFC. LCMS theoretical m/z=493.2. [M+H]+, found 494.2.

Example 340, Compound 320

N-(2,6-dichlorobenzoyl)-O—((R)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme I using General Procedure N with 2,6-dichlorobenzoic acid. The title compound was isolated as the fourth eluting isomer by SFC. LCMS theoretical m/z=493.2. [M+H]+, found 494.2.

Example 341, Compound 321

N-(2-chloro-6-fluorobenzoyl)-O—((S)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Prepared according to General Scheme I using General Procedure N with 2-chloro-6-fluorobenzoic acid. The title compound was isolated as the first eluting isomer by SFC. LCMS theoretical m/z=477.2 [M+H]+, found 478.1.

Example 342, Compound 322

N-(2-chloro-6-fluorobenzoyl)-O—((R)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Prepared according to General Scheme I using General Procedure N with 2-chloro-6-fluorobenzoic acid. The title compound was isolated as the second eluting isomer by SFC. LCMS theoretical m/z=477.2 [M+H]+, found 478.1.

Example 343, Compound 323

N-(2-chloro-6-fluorobenzoyl)-O—((S)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme I using General Procedure N with 2-chloro-6-fluorobenzoic acid. The title compound was isolated as the third eluting isomer by SFC. LCMS theoretical m/z=477.2 [M+H]+, found 478.1.

Example 344, Compound 324

N-(2-chloro-6-fluorobenzoyl)-O—((R)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme I using General Procedure N with 2-chloro-6-fluorobenzoic acid. The title compound was isolated as the fourth eluting isomer by SFC. LCMS theoretical m/z=477.2 [M+H]+, found 478.1.

Example 345, Compound 325

N-(4-fluoro-2-methylnicotinoyl)-O—((S)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Prepared according to General Scheme I using General Procedure N with 4-fluoro-2-methylnicotinic acid. The title compound was isolated as the first eluting isomer by SFC. LCMS theoretical m/z=458.2 [M+H]+, found 459.2.

Example 346, Compound 326

N-(4-fluoro-2-methylnicotinoyl)-O—((R)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-L-homoserine

Prepared according to General Scheme I using General Procedure N with 4-fluoro-2-methylnicotinic acid. The title compound was isolated as the second eluting isomer by SFC. LCMS theoretical m/z=458.2. [M+H]+, found 459.2.

Example 347, Compound 327

N-(4-fluoro-2-methylnicotinoyl)-O—((S)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme I using General Procedure N with 4-fluoro-2-methylnicotinic acid. The title compound was isolated as the third eluting isomer by SFC. LCMS theoretical m/z=458.2. [M+H]+, found 459.2.

Example 348, Compound 328

N-(4-fluoro-2-methylnicotinoyl)-O—((R)-2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-D-homoserine

Prepared according to General Scheme I using General Procedure N with 4-fluoro-2-methylnicotinic acid. The title compound was isolated as the fourth eluting isomer by SFC. LCMS theoretical m/z=458.2. [M+H]+, found 459.2.

2-(but-3-en-1-yl)-2-methyl-1,3-dioxolane

To a solution of hex-5-en-2-one (18 mL, 155 mmol) in toluene (155 mL) was added ethylene glycol (11.3 mL, 202 mmol) and p-toluenesulfonic acid monohydrate (2.96 g, 15.5 mmol)), and the resulting mixture was stirred at 110° C. overnight and was diluted with water and EtOAc. The layers were separated, and the aqueous layer was extracted with EtOAc. The combined organic layers were washed with water and brine, dried over Na₂SO₄, filtered, and concentrated in vacuo to give the title compound, which was used without further purification

2-methyl-2-(2-(oxiran-2-yl)ethyl)-, 3-dioxolane

To a solution of 2-(but-3-en-1-yl)-2-methyl-1,3-dioxolane (15.8 g, 111 mmol) in DCM (200 mL) was added m-chloroperoxybenzoic acid (23 g, 134 mmol), and the resulting mixture was stirred at rt overnight was diluted with water and DCM. The layers were separated, and the aqueous layer was extracted with DCM. The combined organic layers were washed with water and brine, dried over Na₂SO₄, filtered, and concentrated in vacuo to give the title compound, which was used without further purification.

(S)-4-(2-methyl-1,3-dioxolan-2-yl)butane-1,2-diol

To a solution of 2-methyl-2-(2-(oxiran-2-yl)ethyl)-1,3-dioxolane (5.3 g, 33 mmol) in toluene (67 mL) was added (R,R)-(−)-N,N″-bis(3,5-di-tertbutylsalicylidene)-1,2-cyclohexanediaminocobalt(II) (40.55 mg, 0.07 mmol), acetic acid (0.04 mL, 0.67 mmol), and water (0.33 mL, 18.5 mmol) and the resulting mixture was allowed to stir at rt overnight rt overnight and then was concentrated in vacuo. The crude residue was purified by silica gel chromatography to give the title compound.

(S)-1-(allyloxy)-4-(2-methyl-1,3-dioxolan-2-yl)butan-2-ol

To a solution of (S)-4-(2-methyl-1,3-dioxolan-2-yl)butane-1,2-diol (1.8 g, 10.2 mmol) in THF (34 mL) was added NaH (410 mg, 10.2 mmol) at 0° C. and the resulting mixture was stirred at rt. After 1 h, allyl bromide (0.9 mL, 10.2 mmol) was added and the resulting mixture was allowed to stir at rt overnight and was concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give the title compound.

(S)-((1-(allyloxy)-4-(2-methyl-1,3-dioxolan-2-yl)butan-2-yl)oxy) (tert-butyl)dimethylsilane

To a solution of (S)-1-(allyloxy)-4-(2-methyl-1,3-dioxolan-2-yl)butan-2-ol (1.00 g, 4.6 mmol) in CH₂Cl₂ (9 mL) was added imidazole (1.1 g, 16 mmol) and TBSCl (1.8 mL, 6.9 mmol) and the resulting mixture was allowed to stir at rt for 10 min. The reaction mixture was diluted with saturated sodium bicarbonate and CH₂Cl₂. The combined organic layers were washed with water and brine, dried over Na₂SO₄, filtered, and concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to give the title compound.

(S)-2-(2-((tert-butyldimethylsilyl)oxy)-4-(2-methyl-1,3-dioxolan-2-yl)butoxy)acetaldehyde

To a solution of (S)-((1-(allyloxy)-4-(2-methyl-1,3-dioxolan-2-yl)butan-2-yl)oxy)(tert-butyl)dimethylsilane (1.1 g, 2.4 mmol) in 3:1 THF/H₂O (15 mL) was added NaIO4 (2.1 g, 9.7 mmol) and OsO₄ (0.04 mL, 0.121 mmol) and the resulting mixture was allowed to stir at rt for 3 h and was diluted with saturated sodium bicarbonate, saturated sodium thiosulfate, and EtOAc. The layers were separated and the aqueous layer was extracted EtOAc. The combined organic layers were washed with water and brine, dried over Na₂SO₄, filtered, and concentrated in vacuo to give the title compound which was used without further purification.

methyl (S,E)-2-((tert-butoxycarbonyl)amino)-4-(2-((tert-butyldimethylsilyl)oxy)-4-(2-methyl-1,3-dioxolan-2-yl)butoxy)but-2-enoate

To a solution of (S)-2-(2-((tert-butyldimethylsilyl)oxy)-4-(2-methyl-1,3-dioxolan-2-yl)butoxy)acetaldehyde (1.1 mg, 2.4 mmol) in CH₂Cl₂ (6 mL) was added methyl 2-((tert-butoxycarbonyl)amino)-2-(dimethoxyphosphoryl)acetate (718 mg, 5.3 mmol) and DBU (0.53 mL, 3.50 mmol) and the resulting mixture was allowed to stir at rt for 2 h and then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give the title compound.

methyl (S,E)-2-((tert-butoxycarbonyl)amino)-4-((2-((tert-butyldimethylsilyl)oxy)-5-oxohexyl)oxy)but-2-enoate

To a solution of methyl (S,E)-2-((tert-butoxycarbonyl)amino)-4-(2-((tert-butyldimethylsilyl)oxy)-4-(2-methyl-1,3-dioxolan-2-yl)butoxy)but-2-enoate (12.4 mg, 0.02 mmol) in CH₃CN/H2O 4:1 (0.5 mL) was added DDQ (0.9 mg, 0.004 mmol) and the resulting mixture was allowed to stir at rt for 2 h and then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give the title compound.

methyl N-(tert-butoxycarbonyl)-O—((S)-2-((tert-butyldimethylsilyl)oxy)-5-oxohexyl)homoserinate

To a solution of methyl methyl (S,E)-2-((tert-butoxycarbonyl)amino)-4-((2-((tert-butyldimethylsilyl)oxy)-5-oxohexyl)oxy)but-2-enoate (195 mg, 0.334 mmol) in MeOH (2 mL) was added Pd(OH)₂/C (20 wt % on carbon, 20 mg) and the resulting mixture was stirred under an H₂ atmosphere overnight and was filtered through Celite then concentrated in vacuo to give the title compound which was without further purification.

methyl N-(tert-butoxycarbonyl)-O—((S)-2-((tert-butyldimethylsilyl)oxy)-4-(1,8-naphthyridin-2-yl)butyl)homoserinate

To a solution of methyl N-(tert-butoxycarbonyl)-O—((S)-2-((tert-butyldimethyl silyl)oxy)-5-oxohexyl)homoserinate (200 mg, 0.341 mmol) in EtOH (1 mL) was added L-proline (27.5 mg, 0.239 mmol) and 2-aminonicotinaldehyde (83.4 mg, 0.683 mmol) and the resulting mixture was stirred at 75° C. overnight and was then concentrated in vacuo. The crude residue was purified by normal phase column chromatography to give the title compound.

methyl N-(tert-butoxycarbonyl)-O—((S)-2-((tert-butyldimethylsilyl)oxy)-4-(1,8-naphthyridin-2-yl)butyl)homoserinate

To a solution of methyl N-(tert-butoxycarbonyl)-O—((S)-2-((tert-butyldimethyl silyl)oxy)-4-(1,8-naphthyridin-2-yl)butyl)homoserinate (67.1 mg, 0.10 mmol) in MeOH (2 mL) was added Pd(OH)₂/C (20 wt % on carbon, 20 mg) and the resulting mixture was stirred under an H₂ atmosphere overnight and was filtered through Celite then concentrated in vacuo. The crude residue was purified by normal phase silica gel chromatography to the title compound.

methyl O—((S)-2-((tert-butyldimethylsilyl)oxy)-4-(1,8-naphthyridin-2-yl)butyl)homoserinate

To a solution of methyl N-(tert-butoxycarbonyl)-O—((S)-2-((tert-butyldimethylsilyl)oxy)-4-(1,8-naphthyridin-2-yl)butyl)homoserinate (35.0 mg, 0.052 mmol) in DCM (0.1 mL) was added 4 N HCl in 1,4-dioxane (0.06 mL, 0.207 mmol) and the resulting mixture was allowed to stir at rt overnight then was concentrated in vacuo to give the title compound which was used without further purification.

methyl N-(3-chloro-5-fluoroisonicotinoyl)-O—((S)-2-hydroxy-4-(1,8-naphthyridin-2-yl)butyl)homoserinate

To a solution of methyl 4-[(2S)-2-[tert-butyl(diphenyl)silyl]oxy-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]-2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]butanoate (38.0 mg, 0.0518 mmol) in THF (0.1 mL) was added tetrabutylammonium fluoride (0.06 mL, 0.0622 mmol) and the resulting mixture was allowed to stir at rt for 2 h and was diluted with saturated NH4C₁. The layers were separated and the aqueous layer was extracted CH₂Cl₂. The combined organic layers were washed with water and brine, dried over Na₂SO₄, filtered, and concentrated in vacuo to give the title compound which was used without further purification.

Example 349, Compound 329

N-(3-chloro-5-fluoroisonicotinoyl)-O—((S)-2-hydroxy-4-(1,8-naphthyridin-2-yl)butyl)homoserine

To a solution of methyl N-(3-chloro-5-fluoroisonicotinoyl)-O—((S)-2-hydroxy-4-(1,8-naphthyridin-2-yl)butyl)homoserinate (25.6 mg, 0.0518 mmol) in THF/MeOH/H2O 3:1:1 was added LiOH (9.9 mg, 0.41 mmol) and the resulting mixture was allowed to stir at rt for 4 h. LCMS showed conversion to product, and the reaction mixture was diluted with water and purified by reverse phase preparative HPLC to afford N-(3-chloro-5-fluoroisonicotinoyl)-O—((S)-2-hydroxy-4-(1,8-naphthyridin-2-yl)butyl)homoserine as a TFA salt.

N-(3-chloro-5-fluoroisonicotinoyl)-O—((S)-2-hydroxy-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine. (Compound 329, Alternate Preparation)

Prepared according to General Scheme J using General Procedure I with 3-chloro-5-fluoroisonicotinic acid and General Procedure N. The mixture was neutralized with AcOH and then purified by preparative reverse phase HPLC to the title compound as a trifluoroacetic acid salt. LCMS theoretical m/z=480.2. [M+H]+, found 481.1.

Example 350, Compound 10

(S)-2-(1-methyl-1H-indazole-4-carboxamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic Acid

Prepared according to Example 2 with the exception that the acid was replaced by 1-methyl-1H-indazole-4-carboxylic acid in the reaction with intermediate 2i. LCMS theoretical m/z=465.2. [M+H]+, found 466.1.

Example 351, Compound 11

(S)-2-(3-(1-methyl-1H-pyrazol-4-yl)benzamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic Acid

Prepared according to Example 2 with the exception that the acid was replaced by 3-(1-methyl-1H-pyrazol-4-yl)benzoic acid in the reaction with intermediate 2i. LCMS theoretical m/z=491.2. [M+H]+, found 492.2.

Example 352, Compound 12

(S)-2-(2-chloro-3-fluorobenzamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic Acid

Prepared according to Example 2 with the exception that the bromide was replaced with 6-bromohex-1-ene in the reaction with intermediate 2d and the acid was replaced by 2-chloro-3-fluorobenzoic acid in the reaction with intermediate 2i. LCMS theoretical m/z=463.2. [M+H]+, found 464.1.

Example 353, Compound 13

(S)-2-(3-(1-methyl-1H-pyrazol-4-yl)benzamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic Acid

Prepared according to Example 2 with the exception that the bromide was replaced with 6-bromohex-1-ene in the reaction with intermediate 2d and the acid was replaced by 3-(1-methyl-1H-pyrazol-4-yl)benzoic acid in the reaction with intermediate 2i. LCMS theoretical m/z=491.2. [M+H]+, found 492.2.

Example 354, Compound 16

(S)-2-(2-ethylbutanamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic Acid

Prepared according to Example 2 with the exception that the bromide was replaced with 6-bromohex-1-ene in the reaction with intermediate 2d and the acid was replaced by 2-ethylbutanoic acid in the reaction with intermediate 2i. LCMS theoretical m/z=405.2. [M+H]+, found 406.2.

Example 355, Compound 17

(S)-2-(1-methyl-1H-indazole-4-carboxamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic Acid

Prepared according to Example 2 with the exception that the bromide was replaced with 6-bromohex-1-ene in the reaction with intermediate 2d and the acid was replaced by 1-methyl-1H-indazole-4-carboxylic acid in the reaction with intermediate 2i. LCMS theoretical m/z=465.2. [M+H]+, found 466.2.

Example 356, Compound 20

(S)-2-((tert-butoxycarbonyl)amino)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic Acid

Prepared according to Example 2 with the exception that the acid was replaced by di-tert-butyl dicarbonate in the reaction with intermediate 2i. LCMS theoretical m/z=407.2. [M+H]+, found 408.2.

Example 357, Compound 21

N-benzoyl-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer D2 was employed in General Scheme D-2 using General Procedure I with benzoic acid. LCMS theoretical m/z=437.2. [M+H]+, found 438.8.

Example 358, Compound 178

N-(quinazolin-4-yl)-O-((1r,3s)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure E with 4-chloroquinazoline. LCMS theoretical m/z=461.2. [M+H]+, found 462.3.

Example 359, Compound 179

N-(8-fluoroquinazolin-4-yl)-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure E with 4-chloro-8-fluoroquinazoline. LCMS theoretical m/z=479.2. [M+H]+, found 480.2.

Example 360, Compound 180

N-(7-fluoroquinazolin-4-yl)-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure E with 4-chloro-7-fluoroquinazoline. LCMS theoretical m/z=479.2. [M+H]+, found 480.2.

Example 361, Compound 181

N-(7-methylquinazolin-4-yl)-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure E with 4-chloro-7-methylquinazoline. LCMS theoretical m/z=475.3. [M+H]+, found 476.3.

Example 362, Compound 182

N-(6-fluoroquinazolin-4-yl)-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure E with 4-chloro-6-fluoroquinazoline. LCMS theoretical m/z=479.2. [M+H]+, found 480.2.

Example 363, Compound 183

N-(5-fluoroquinazolin-4-yl)-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure E with 4-chloro-5-fluoroquinazoline. LCMS theoretical m/z=479.2. [M+H]+, found 480.2.

Example 364, Compound 184

N-(6-methylquinazolin-4-yl)-O-((1s,3r)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure E with 4-chloro-6-methylquinazoline. LCMS theoretical m/z=475.3. [M+H]+, found 476.3.

Example 365, Compound 185

N-(6-(tert-butyl)-2-phenylpyrimidin-4-yl)-O-((1s,3S)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-L-homoserine

Isomer E2 was employed in General Scheme E-2 using General Procedure E with 4-(tert-butyl)-6-chloro-2-phenylpyrimidine. LCMS theoretical m/z=543.3. [M+H]+, found 544.3.

Example 366, Compound 23

(S)-2-((tert-butoxycarbonyl)amino)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic Acid

Was prepared by the same procedure used to prepare Example 2 with the exception that the bromide was replaced with 6-bromohex-1-ene in the reaction with intermediate 2d and the acid was replaced by di-tert-butyl dicarbonate in the reaction with intermediate 2i. LCMS theoretical m/z=407.2. [M+H]+, found 408.2.

BIOLOGICAL EXAMPLES Example B1—Proximity-Based Integrin Receptor Binding Assay for Determining Inhibitor Potency

The biochemical potency of compounds was determined using a proximity-based assay (ALPHASCREEN®, Perkin Elmer, Waltham, Mass.) as described previously (Ullman E F et al., Luminescent oxygen channeling immunoassay: Measurement of particle binding kinetics by chemiluminescence. Proc. Natl. Acad. Sci. USA, Vol. 91, pp. 5426-5430, June 1994). To gauge the potency of inhibitors of binding to human integrin αvβ6, inhibitor compounds and integrin were incubated together with TGF-b1 LAP and biotinylated anti-LAP antibody plus acceptor and donor beads, following the manufacture's recommendations. The donor beads were coated with streptavidin. The acceptor beads had a nitrilotriacetic acid Ni chelator, for binding to a 6×His Tag on human integrin αvβ6. All incubations occurred at room temperatures in 50 mM Tris-HCl, pH 7.5, 0.1% BSA supplemented with 1 mM each CaCl₂ and MgCl₂.

The order of reagent addition was as follows:

1. Alpha-v-beta-6 integrin, test inhibitor compound, LAP, biotinylated anti-LAP antibody and acceptor beads were all added together.

2. After 2 hours, donor beads were added. After another 30 minute incubation, samples were then read.

Integrin binding was evaluated by exciting donor beads at 680 nm, and measuring the fluorescent signal produced, between 520-620 nm, using a Biotek Instruments (Winooski, Vt., USA) SynergyNeo2 multimode plate reader. Compound potency was assessed by determining inhibitor concentrations required to reduce fluorescent light output by 50%. Data analysis for IC₅₀ determinations was carried out by nonlinear four parameter logistic regression analysis using Dotmatics ELN Software (Core Informatics Inc., Branford, Conn.). IC₅₀ values for the compounds in the Examples are provided below in Table B-1 in ranges: below 50 nM; from above 50 nM to 250 nM; from above 250 nM to 1000 nM; and above 1000 nM.

TABLE B-1 Example Example No. IC50 (nM) No. IC50 (nM)  1 <50  4 >1000   5 >50-250  6 >250-1000  7 >50-250  8 >250-1000  9 >50-250  10 >50-250  11 >50-250  12A >50-250  13 >250-1000  14 <50  15 <50  16 <50  17 <50  18 >50-250  19 <50  20 <50  21 <50  22 <50  23 <50  24 <50  25 <50  26 <50  27 <50  28 <50  29 <50  30 <50  31 <50  32 <50  33 <50  34 >50-250  35 >50-250  36 <50  37 <50  38 >50-250  39 >50-250  40 >50-250  41 <50  42† >50-250  43†† >250-1000  44 >50-250  45 >50-250  46† >250-1000  47†† >250-1000  48 >250-1000  49 >50-250  50 <50  51 <50  52 <50  53 >50-250  54 >50-250  55 >250-1000  56 >50-250  57 >250-1000  58* >1000   59* >1000   60* >50-250  61* >1000   62** <50  63** <50  64** <50  65** <50  66 >50-250  67 >50-250  68 >250-1000  69 >250-1000  70† >50-250  71†† >1000   72 <50  73 >50-250  74† >1000   75†† >250-1000  76† >250-1000  77†† >1000   78† >1000   79†† >50-250  80† >50-250  81†† >1000   82* >250-1000  83* >1000   84* <50  85* >250-1000  86* >250-1000  87* >250-1000  88* >50-250  89* >250-1000  90* >250-1000  91* >50-250  92* >250-1000  93* >50-250  94* >50-250  95*,† >1000   96*,†† >250-1000  97** <50  98** <50  99** <50 100** >50-250 101** <50 102** <50 103** <50 104** <50 105** <50 106** <50 107** <50 108** <50 109** <50 110**,† >50-250 111**,†† <50 112** >50-250 113** <50 114** <50 115** <50 116** <50 117** <50 118** <50 119** >50-250 120** <50 121** <50 122** >50-250 123** <50 124** <50 125** >50-250 126** <50 127** <50 128** >50-250 129** >50-250 130** >50-250 131** <50 132** >50-250 133** <50 134** >50-250 135** >50-250 136** <50 137** >250-1000 138** >50-250 139** >1000  140** >250-1000 141** <50 142** >50-250 143** >250-1000 144** >250-1000 145A†† >250-1000 145B† >50-250 146** >50-250 147** <50 148** >250-1000 149** >50-250 150** >250-1000 151** <50 152** <50 153** <50 154** >250-1000 155**,† <50 155**,†† <50 157** <50 158** <50 159** <50 160** >50-250 161** <50 162**,†† <50 163**,† >50-250 163**,†† >50-250 164** <50 165** <50 166** >50-250 168** >50-250 169** >50-250 170** <50 171** <50 172** <50 173** <50 174** <50 175**† <50 175**†† <50 176**† <50 176**†† >50-250 177** >50-250 179** >50-250 180**† <50 180**†† >50-250 181** <50 182** >50-250 183** >50-250 184** <50 185** <50 187 >250-1000 188 >50-250 189 >50-250 190** <50 199** >50-250 224 <50 225** >250-1000 226** >250-1000 227* >250-1000 228** <50 229** >50-250 *first eluting compound from general synthetic scheme referenced was assayed **second eluting compound from general synthetic scheme referenced was assayed †first eluting compound from last chromatography step described in example was assayed ††second eluting compound from last chromatography step described in example was assayed

Example B2—Further Compounds Potently Inhibit αvβ₆ in a Proximity-Based Assay

The biochemical potency of compounds for inhibiting αvβ₆ integrin was determined for a second series of compounds using a proximity-based assay (ALPHASCREEN®, Perkin Elmer, Waltham, Mass.) as described previously (Ullman E F et al., Luminescent oxygen channeling immunoassay: Measurement of particle binding kinetics by chemiluminescence. Proc. Natl. Acad. Sci. USA, Vol. 91, pp. 5426-5430, June 1994). To gauge the potency of inhibitors of binding to human integrin α_(v)β₆, inhibitor compounds and integrin were incubated together with TGF-b1 LAP and biotinylated anti-LAP antibody plus acceptor and donor beads, following the manufacture's recommendations. The donor beads were coated with streptavidin. The acceptor beads had a nitrilotriacetic acid Ni chelator, for binding to a 6×His Tag on human integrin α_(v)β6. All incubations occurred at room temperatures in 50 mM Tris-HCl, pH 7.5, 0.1% BSA supplemented with 1 mM each CaCl₂ and MgCl₂.

The order of reagent addition was as follows:

1. Alpha-v-beta-6 integrin, test inhibitor compound, LAP, biotinylated anti-LAP antibody and acceptor beads were all added together.

2. After 2 hours, donor beads were added. After another 30 minute incubation, samples were then read.

Integrin binding was evaluated by exciting donor beads at 680 nm, and measuring the fluorescent signal produced, between 520-620 nm, using a Biotek Instruments (Winooski, Vt., USA) SynergyNeo2 multimode plate reader. Compound potency was assessed by determining inhibitor concentrations required to reduce fluorescent light output by 50%. Data analysis for IC₅₀ determinations was carried out by nonlinear four parameter logistic regression analysis using Dotmatics ELN Software (Core Informatics Inc., Branford, Conn.).

Example B3—The Compounds Potently Inhibit α_(v)β₁ in a Proximity-Based Assay

The biochemical potency of compounds for inhibiting α_(v)β₁ integrin was determined using a proximity-based assay (ALPHASCREEN®, Perkin Elmer, Waltham, Mass.) as described previously (Ullman E F et al., Luminescent oxygen channeling immunoassay: Measurement of particle binding kinetics by chemiluminescence. Proc. Natl. Acad. Sci. USA, Vol. 91, pp. 5426-5430, June 1994). To gauge the potency of inhibitors of binding to human integrin α_(v)β₁, inhibitor compounds and integrin were incubated together with TGF-b1 LAP and biotinylated anti-LAP antibody plus acceptor and donor beads, following the manufacture's recommendations. The donor beads were coated with streptavidin. The acceptor beads had a nitrilotriacetic acid Ni chelator, for binding to a 6×His Tag on human integrin α_(v)β₁. All incubations occurred at room temperatures in 50 mM Tris-HCl, pH 7.5, 0.1% BSA supplemented with 1 mM each CaCl₂ and MgCl₂.

The order of reagent addition was as follows:

1. Alpha-v-beta-1 integrin, test inhibitor compound, LAP, biotinylated anti-LAP antibody and acceptor beads were all added together.

2. After 2 hours, donor beads were added. After another 30 minute incubation, samples were then read.

Integrin binding was evaluated by exciting donor beads at 680 nm, and measuring the fluorescent signal produced, between 520-620 nm, using a Biotek Instruments (Winooski, Vt., USA) SynergyNeo2 multimode plate reader. Compound potency was assessed by determining inhibitor concentrations required to reduce fluorescent light output by 50%. Data analysis for IC₅₀ determinations was carried out by nonlinear four parameter logistic regression analysis using Dotmatics ELN Software (Core Informatics Inc., Branford, Conn.). IC₅₀ values for the compounds in the Examples are provided in FIG. 2, Table B-2 in ranges: 50 nM and below; from above 50 nM to 250 nM; from above 250 nM to 1000 nM; and above 1000 nM.

Combined Inhibition Results of Examples B1, B2, and B3

Table B-2, FIG. 2, shows IC₅₀ data from Examples B1, B2, and B3 for inhibition of αvβ₁ and αvβ₆ integrin in the solid phase assays and inhibition of human αvβ₁ and αvβ₆ integrin in the proximity-based ALPHASCREEN® assays. The IC₅₀ data is shown in four ranges: 50 nM and below; from 50 nM to below 250 nM; from above 250 nM to below 1000 nM; and 1000 nM and above. 

What is claimed is:
 1. A compound of formula (I):

or a salt thereof, wherein: R¹ is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl optionally substituted by R⁴, 1,2,3,4-tetrahydro-1,8-naphthyridin-2-yl optionally substituted by R⁴, 6-aminopyridin-2-yl optionally substituted by R⁴, or (pyridin-2-yl)amino optionally substituted by R⁴; G is —C(O)R² or R³; R² is C₁-C₆ alkyl optionally substituted by R^(2a), C₃-C₈ cycloalkyl optionally substituted by R^(2b), 3- to 12-membered heterocyclyl optionally substituted by R^(2c), C₆-C₁₄ aryl optionally substituted by R^(2d), 5- to 10-membered heteroaryl optionally substituted by R^(2e), —OR^(2f), or —NR^(2g)R^(2h); R³ is C₁-C₆ alkyl optionally substituted by R^(3a), C₃-C₈ cycloalkyl optionally substituted by R^(3b), 3- to 12-membered heterocyclyl optionally substituted by R^(3c), C₆-C₁₄ aryl optionally substituted by R^(3d), or 5- to 10-membered heteroaryl optionally substituted by R^(3e); L¹ is C₂-C₄ alkylene optionally substituted by R⁴; L² is a bond or C₁-C₃ alkylene optionally substituted by R⁴; L³ is C₂-C₄ alkylene optionally substituted by R⁴; Y is a bond or C₃-C₈ cycloalkylene optionally substituted by Y^(a); R^(2f) is C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, or 5- to 10-membered heteroaryl, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2f) are independently optionally substituted by R^(2i); R^(2g) and R^(2h) are each independently hydrogen, deuterium, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, or 5- to 10-membered heteroaryl, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2g) and R^(2h) are independently optionally substituted by R^(2j); each R^(2a), R^(2b), R^(2c), R^(2d), R^(2e), R^(2i), R^(2j), R^(3a), R^(3b), R^(3c), R^(3d), R^(3e) and Y^(a) is independently oxo or R⁴; each R⁴ is independently deuterium, halogen, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, —CN, —OR⁵, —SR⁵, —NR⁶R⁷, —NO₂, —C═NH(OR⁵), —C(O)R⁵, —OC(O)R⁵, —C(O)OR⁵, —C(O)NR⁶R⁷, —NR⁵C(O)R⁶, —NR⁵C(O)OR⁶, —NR⁵C(O)NR⁶R⁷, —S(O)R⁵, —S(O)₂R⁵, —NR⁵S(O)R⁶, —NR⁵S(O)₂R⁶, —S(O)NR⁶R⁷, —S(O)₂NR⁶R⁷, or —P(O)(OR⁵)(OR⁶), wherein the C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R⁴ are independently optionally substituted by R^(4a); each R^(4a) is independently deuterium, halogen, oxo, —OR, —NR⁸R⁹, —C(O)R⁸, —C(O)OR⁸, —NR⁸C(O)OR¹⁰, —CN, —S(O)R⁸, —S(O)₂R⁸, —P(O)(OR⁸)(OR⁹), C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, 5- to 10-membered heteroaryl, C₆-C₁₄ aryl, or C₁-C₆ alkyl, wherein the 3- to 12-membered heterocyclyl, 5- to 10-membered heteroaryl, C₆-C₁₄ aryl, and C₁-C₆ alkyl of R^(4a) are independently optionally substituted by R^(4b); each R^(4b) is independently deuterium, oxo, —OH, —O(²H), halogen, or C₁-C₆ alkyl optionally substituted by deuterium, halogen, —OH, —O(²H), or oxo; each R⁵ is independently hydrogen, deuterium, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, or 3- to 10-membered heterocyclyl, wherein the C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, and 3- to 10-membered heterocyclyl of R⁵ are each independently optionally substituted by R^(5a); each R^(5a) is independently halogen, deuterium, oxo, —CN, —OR¹⁰, —NR¹¹R¹², —P(O)(OR¹¹)(OR¹²), 3- to 12-membered heterocyclyl, or C₁-C₆ alkyl optionally substituted by deuterium, halogen, —OH, —O(²H), or oxo; each R⁶ is independently hydrogen, deuterium, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, or 3- to 6-membered heterocyclyl, wherein the C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, and 3- to 6-membered heterocyclyl of R⁶ are independently optionally substituted by deuterium, halogen, oxo, —CN, —OR¹⁰, —NR¹¹R¹², or C₁-C₆ alkyl optionally substituted by deuterium, halogen, —OH, —O(²H), or oxo; each R⁷ is independently hydrogen, deuterium, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, or 3- to 6-membered heterocyclyl, wherein the C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, and 3- to 6-membered heterocyclyl of R⁷ are independently optionally substituted by deuterium, halogen, oxo, —CN, —OR¹⁰, —NR¹¹R¹², or C₁-C₆ alkyl optionally substituted by deuterium, halogen, —OH, —O(²H), or oxo; or R⁶ and R⁷ are taken together with the atom to which they are attached to form a 3- to 10-membered heterocyclyl optionally substituted by deuterium, halogen, oxo, —OR¹⁰, —NR¹¹R¹², or C₁-C₆ alkyl optionally substituted by deuterium, halogen, oxo, —OH, or —O(²H); each R⁸ is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo; each R⁹ is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo; each R¹⁰ is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo; each R¹¹ is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo; and each R¹² is independently hydrogen, deuterium, C₁-C₆ alkyl optionally substituted by deuterium, halogen, or oxo, C₂-C₆ alkenyl optionally substituted by deuterium, halogen, or oxo, or C₂-C₆ alkynyl optionally substituted by deuterium, halogen, or oxo; or R¹¹ and R¹² are taken together with the atom to which they are attached to form a 3-6 membered heterocyclyl optionally substituted by deuterium, halogen, oxo or C₁-C₆ alkyl optionally substituted by deuterium, oxo, or halogen.
 2. The compound of claim 1, or a salt thereof, wherein L¹ is C₂ alkylene optionally substituted by R¹⁰.
 3. The compound of claim 2, or a salt thereof, wherein L¹ is —CH₂CH₂—.
 4. The compound of claim 1, or a salt thereof, wherein at least one of R^(2g), R^(2h), R^(2a), R^(2b), R^(2c), R^(2d), R^(2e), R^(2i), R^(2j), R^(3a), R^(3b), R^(3c), R^(3d), R^(3e), Y^(a), R^(4a), R^(4b), R⁵, R^(5a), R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, or R¹² is deuterium.
 5. The compound of claim 1, or a salt thereof, wherein -L¹-O-L²-Y-L³- are taken together to form a moiety selected from the group consisting of:

wherein

is a C₃-C₈ cycloalkylene optionally substituted by Y^(a), and

wherein

is a C₃-C₈ cycloalkylene optionally substituted by Y^(a).
 6. The compound of claim 5, or a salt thereof, wherein -L¹-O-L²-Y-L³- are taken together to form a moiety selected from the group consisting of:


7. The compound of claim 5, or a salt thereof, wherein -L¹-O-L²-Y-L³- are taken together to form a moiety selected from the group consisting of:


8. The compound of claim 5, or a salt thereof, wherein -L¹-O-L²-Y-L³- are taken together to form a moiety selected from the group consisting of:


9. The compound of any one of claims 1-8, or a salt thereof, wherein G is —C(O)R².
 10. The compound of claim 9, or a salt thereof, wherein R² is C₁-C₆ alkyl substituted by 0-5 R^(2a) groups.
 11. The compound of claim 9, or a salt thereof, wherein R² is unsubstituted C₁-C₆ alkyl.
 12. The compound of claim 9, or a salt thereof, wherein R² is unsubstituted C₄-C₆ alkyl.
 13. The compound of claim 9, or a salt thereof, wherein R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein each R^(2a) is independently selected from halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, —CN, —OR⁵, —NR⁶R⁷, —NR⁵C(O)OR⁶, and —S(O)₂R⁵, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2a) are independently optionally substituted by R^(4a).
 14. The compound of claim 12, or a salt thereof, wherein R² is C₂-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is halogen.
 15. The compound of claim 12, or a salt thereof, wherein R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is C₃-C₈ cycloalkyl.
 16. The compound of claim 12, or a salt thereof, wherein R² is C₁-C₃ alkyl substituted by C₃-C₆ cycloalkyl, wherein the C₃-C₆ cycloalkyl is substituted by 0-5 groups selected from the group consisting of halogen, C₁-C₆ alkyl, and —OR⁵.
 17. The compound of claim 12, or a salt thereof, wherein R² is C₁-C₃ alkyl substituted by C₃-C₆ cycloalkyl, wherein the C₃-C₆ cycloalkyl unsubstituted.
 18. The compound of claim 12, or a salt thereof, wherein R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is 3- to 12-membered heterocyclyl.
 19. The compound of claim 12, or a salt thereof, wherein R² is C₁ alkyl substituted by 6-membered heterocyclyl.
 20. The compound of claim 12, or a salt thereof, wherein R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is C₆-C₁₄ aryl, wherein the C₆-C₁₄ aryl is independently optionally substituted by halogen or C₁-C₆ alkyl substituted by 0-5 halogen.
 21. The compound of claim 19, or a salt thereof, wherein R^(2a) is unsubstituted phenyl or phenyl substituted by 1-5 halogen.
 22. The compound of claim 12, or a salt thereof, wherein R² is C₂-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is 5- to 10-membered heteroaryl substituted by 0-5 R^(4a) groups.
 23. The compound of claim 21, or a salt thereof, wherein R^(2a) is unsubstituted pyridinyl.
 24. The compound of claim 12, or a salt thereof, wherein R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is —OR⁵, wherein each R⁵ is independently selected from hydrogen, C₁-C₆ alkyl, and C₆-C₁₄ aryl.
 25. The compound of claim 23, or a salt thereof, wherein R⁵ is C₆-C₁₄ aryl substituted by 0-5 halogen.
 26. The compound of claim 12, or a salt thereof, wherein R² is C₁-C₅ alkyl substituted by 1-5 R^(2a) groups, wherein at least one of the R^(2a) groups is —CN, —NR⁶R⁷, —NR⁵C(O)OR⁶, or —S(O)₂R⁵.
 27. The compound of claim 12, or a salt thereof, wherein R² is C₁-C₅ alkyl substituted by 2-5 R^(2a) groups, wherein each R^(2a) is independently selected from halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 5- to 10-membered heteroaryl, C₆-C₁₄ aryl, —CN, —OR⁵, and —NR⁵C(O)OR⁶.
 28. The compound of claim 26, or a salt thereof, wherein R² is C₁-C₅ alkyl substituted by 2-5 R^(2a) groups, wherein at least one R^(2a) group is phenyl substituted by 0-5 halogen and at least one R^(2a) group is OR⁵, wherein each R⁵ is independently selected from hydrogen and C₁-C₆ alkyl.
 29. The compound of claim 9, or a salt thereof, wherein R² is C₃-C₈ cycloalkyl substituted by 0-5 R^(2b) groups.
 30. The compound of claim 28, or a salt thereof, wherein R² unsubstituted C₃-C₈ cycloalkyl.
 31. The compound of claim 28, or a salt thereof, wherein R² is C₃-C₈ cycloalkyl substituted by 1-5 R^(2b) groups, wherein each R^(2b) is independently selected from halogen, C₁-C₆ alkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, and —OR⁵.
 32. The compound of claim 30, or a salt thereof, wherein R² is C₃-C₆ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is halogen.
 33. The compound of claim 30, or a salt thereof, wherein R² is C₃-C₆ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is C₁-C₆ alkyl, wherein the C₁-C₆ alkyl of R^(2b) is substituted by 0-5 R^(4a) groups.
 34. The compound of claim 30, or a salt thereof, wherein R^(2b) is C₁-C₂ alkyl substituted by 1-5 R^(4a) groups, wherein each R⁴a groups is independently selected from phenyl substituted by 0-5 halogen and 6-membered heteroaryl substituted by 0-5 halogen.
 35. The compound of claim 30, or a salt thereof, wherein R² is C₃-C₆ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is 3- to 12-membered heterocyclyl.
 36. The compound of claim 34, or a salt thereof, wherein R^(2b) is tetrahydro-2H-pyranyl or benzodioxolyl.
 37. The compound of claim 30, or a salt thereof, wherein R² is C₃-C₄ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is C₆-C₁₄ aryl substituted by 0-5 R⁴a groups, wherein each R⁴a is independently selected from halogen, C₁-C₆ alkyl, and —OR⁸.
 38. The compound of claim 30, or a salt thereof, wherein R² is C₃-C₇ cycloalkyl substituted by 1-5 R^(2b) groups, wherein at least one of the R^(2b) groups is 5- to 10-membered heteroaryl.
 39. The compound of claim 37, or a salt thereof, wherein R^(2b) is pyridinyl or isoquinolinyl.
 40. The compound of claim 30, or a salt thereof, wherein R² is C₃-C₆ cycloalkyl substituted by 2-5 R^(2b) groups, wherein each R^(2b) is independently selected from halogen, C₁-C₆ alkyl, C₆-C₁₄ aryl, and —OR⁵.
 41. The compound of claim 39, or a salt thereof, wherein R² is C₃-C₆ cycloalkyl substituted by 2-5 R^(2b) groups, wherein at least one R^(2b) group is halogen and at least one R^(2b) group is phenyl substituted by 0-5 C₁-C₆ alkyl.
 42. The compound of claim 9, or a salt thereof, wherein R² is 3- to 12-membered heterocyclyl substituted by 0-5 R^(2c) groups.
 43. The compound of claim 41, or a salt thereof, wherein R² unsubstituted 4- to 10-membered heterocyclyl.
 44. The compound of claim 41, or a salt thereof, wherein R² is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein each R^(2c) is independently selected from oxo, halogen, C₁-C₆ alkyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, —CN, —OR⁵, —C(O)R⁵, —C(O)OR⁵, and —S(O)₂R⁵.
 45. The compound of claim 43, or a salt thereof, wherein R² is 4- to 6-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein at least one of the R^(2c) groups is C₁-C₆ alkyl, wherein the C₁-C₆ alkyl of R^(2c) is substituted by 0-5 R^(4a) groups.
 46. The compound of claim 44, or a salt thereof, wherein R^(2c) is C₁-C₂ alkyl substituted by 1-5 R^(4a) groups, wherein each R⁴a groups is independently selected from halogen; phenyl substituted by 0-5 halogen; 6-membered heteroaryl substituted by 0-5 halogen; and —NR⁸C(O)OR¹⁰.
 47. The compound of claim 43, or a salt thereof, wherein R² is 4- to 6-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein at least one of the R^(2c) groups is unsubstituted C₆-C₁₄ aryl.
 48. The compound of claim 43, or a salt thereof, wherein R² is 5-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein at least one of the R^(2c) groups is 5- to 10-membered heteroaryl substituted by 0-5 C₁-C₆ alkyl.
 49. The compound of claim 41, or a salt thereof, wherein R² is 4- to 6-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein at least one R^(2c) group is —C(O)R⁵, —C(O)OR⁵, or —S(O)₂R⁵, wherein each R⁵ is independently C₁-C₆ alkyl.
 50. The compound of claim 41, or a salt thereof, wherein R² is 4- to 6-membered heterocyclyl substituted by 1-5 R^(2c) groups, wherein at least one R^(2c) group is oxo.
 51. The compound of claim 41, or a salt thereof, wherein R² is 4- to 6-membered heterocyclyl substituted by 2-5 R^(2c) groups, wherein each R^(2c) is independently selected from halogen, C₁-C₆ alkyl, —C(O)R⁵, and —C(O)OR⁵.
 52. The compound of claim 49, or a salt thereof, wherein R² is 4- to 6-membered heterocyclyl substituted by 2-5 R²C groups, wherein at least one R²C group is C₁-C₆ alkyl substituted by 0-5 halogen and at least one R²C group is —C(O)R⁵ or —C(O)OR⁵.
 53. The compound of claim 41, or a salt thereof, wherein R² is azetidinyl, pyrrolidinyl, piperidinyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, oxabicyclohexanyl, oxabicyclooctanyl, tetrahydro-2H-thiopyranyl, morpholinyl, or benzodioxanyl, each of which is substituted by 0-5 R²C groups.
 54. The compound of claim 9, or a salt thereof, wherein R² is C₆-C₁₄ aryl substituted by 0-5 R^(2d) groups.
 55. The compound of claim 54, or a salt thereof, wherein R² is unsubstituted C₆-C₁₀ aryl.
 56. The compound of claim 54, or a salt thereof, wherein R² is C₆-C₁₀ aryl substituted by 1-5 R^(2d) groups, wherein each R^(2d) is independently selected from halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, 5- to 10-membered heteroaryl, —CN, and —OR⁵, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl and 5- to 10-membered heteroaryl of R^(2d) are each independently substituted by 0-5 halogen, C₁-C₆ alkyl or OR⁸.
 57. The compound of claim 56, or a salt thereof, wherein R² is C₆-C₁₀ aryl substituted by 1-5 R^(2d) groups, wherein at least one of the R^(2d) groups is halogen.
 58. The compound of claim 56, or a salt thereof, wherein R² is C₆-C₁₀ aryl substituted by 1-5 R^(2d) groups, wherein at least one of the R^(2d) groups is C₁-C₆ alkyl, wherein the C₁-C₆ alkyl of R^(2d) is substituted by 0-5 R^(4a) groups.
 59. The compound of claim 58, or a salt thereof, wherein R^(2d) is C₁-C₂ alkyl substituted by 1-5 R^(4a) groups, wherein each R⁴a groups is independently selected from halogen and OR⁸.
 60. The compound of claim 56, or a salt thereof, wherein R² is phenyl substituted by 1-5 R^(2d)groups, wherein at least one of the R^(2d) groups is C₃-C₆ cycloalkyl.
 61. The compound of claim 56, or a salt thereof, wherein R² is phenyl substituted by 1-5 R^(2d)groups, wherein at least one of the R^(2d) groups is 6-membered heterocyclyl.
 62. The compound of claim 56, or a salt thereof, wherein R² is phenyl substituted by 1-5 R^(2d)groups, wherein at least one of the R^(2d) groups is 5- to 6-membered heteroaryl, wherein the heteroaryl of R^(2d) is substituted by 0-5 C₁-C₆ alkyl groups.
 63. The compound of claim 56, or a salt thereof, wherein R² is phenyl substituted by 1-5 R^(2d)groups, wherein at least one of the R^(2d) groups is —OR⁵, wherein each R⁵ is independently selected from C₁-C₂ alkyl substituted by 0-5 groups selected from halogen and —OR¹⁰.
 64. The compound of claim 56, or a salt thereof, wherein R² is phenyl substituted by 2-5 R^(2d)groups, wherein each R^(2d) is independently selected from halogen, C₁-C₆ alkyl, —CN, and —OR⁵.
 65. The compound of claim 64, or a salt thereof, wherein R² is phenyl substituted by 2-5 R^(2d)groups, wherein at least two of the R^(2d) groups are halogen.
 66. The compound of claim 64, or a salt thereof, wherein R² is phenyl substituted by 2-5 R^(2d)groups, wherein at least one of the R^(2d) groups is C₁-C₆ alkyl and at least one of the R^(2d)groups is selected from the group consisting of halogen, —CN, and —OR⁵.
 67. The compound of claim 54, or a salt thereof, wherein R² is phenyl, indanyl, or 1,2,3,4-tetrahydronaphthalenyl, each of which is substituted by 0-5 R^(2d) groups.
 68. The compound of claim 9, or a salt thereof, wherein R² is 5- to 10-membered heteroaryl substituted by 0-5 R^(2e) groups.
 69. The compound of claim 68, or a salt thereof, wherein R² is unsubstituted 5- to 10-membered heteroaryl.
 70. The compound of claim 68, or a salt thereof, wherein R² is 5- to 10-membered heteroaryl substituted by 1-5 R^(2e) groups, wherein each R^(2e) is independently selected from halogen, C₁-C₆ alkyl, and —OR⁵.
 71. The compound of claim 70, or a salt thereof, wherein R² is 5- to 10-membered heteroaryl substituted by 1-5 R^(2e) groups, wherein at least one of the R^(2e) groups is halogen.
 72. The compound of claim 70, or a salt thereof, wherein R² is 5- to 10-membered heteroaryl substituted by 1-5 R^(2e) groups, wherein at least one of the R^(2e) groups is C₁-C₄ alkyl, wherein the C₁-C₄ alkyl of R^(2e) is substituted by 0-5 halogen groups.
 73. The compound of claim 70, or a salt thereof, wherein R² is 5- to 10-membered heteroaryl substituted by 2-5 R²e groups, wherein each R²e is independently selected from halogen, C₁-C₆ alkyl, and —CN.
 74. The compound of claim 73, or a salt thereof, wherein R² is 5- to 10-membered heteroaryl substituted by 2-5 R^(2e) groups, wherein at least two of the R^(2e) groups are halogen.
 75. The compound of claim 73, or a salt thereof, wherein R² is 5- to 10-membered heteroaryl substituted by 2-5 R^(2e) groups, wherein at least two of the R^(2e) groups are C₁-C₆ alkyl.
 76. The compound of claim 73, or a salt thereof, wherein R² is 5- to 10-membered heteroaryl substituted by 3-5 R²e groups, wherein each R²e is independently selected from halogen, C₁-C₆ alkyl, and —CN.
 77. The compound of claim 68, or a salt thereof, wherein R² is pyrazolyl, pyridyl, pyrimidinyl, indazolyl, pyrrolopyridinyl, quinolinyl, or 4,5,6,7-tetrahydro-indazolyl, each of which is substituted by 0-5 R^(2e) groups.
 78. The compound of claim 9, or a salt thereof, wherein R² is —OR^(2f).
 79. The compound of claim 78, or a salt thereof, wherein R² is —OR^(2f), wherein R^(2f) is selected from the group consisting of C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl.
 80. The compound of claim 79, or a salt thereof, wherein R^(2f) is C₁-C₆ alkyl substituted by 0-5 R^(2i) groups.
 81. The compound of claim 80, or a salt thereof, wherein R^(2f) is unsubstituted C₁-C₆ alkyl.
 82. The compound of claim 80, or a salt thereof, wherein R^(2f) is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein each R^(2i) is independently selected from the group consisting of halogen, C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, 5- to 10-membered heteroaryl, —OR⁵, —NR⁵C(O)R⁶, and —NR⁵C(O)OR⁶, wherein the C₁-C₆ alkyl, C₃-C₈ cycloalkyl, 3- to 12-membered heterocyclyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2i) is substituted by 0-5 groups selected from the group consisting of halogen, —CN, —OR⁸, and C₁-C₆ alkyl optionally substituted by halogen.
 83. The compound of claim 82, or a salt thereof, wherein R^(2f) is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein at least one of the R^(2i) groups is halogen.
 84. The compound of claim 82, or a salt thereof, wherein R^(2f) is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein at least one of the R^(2i) groups is phenyl.
 85. The compound of claim 82, or a salt thereof, wherein R^(2f) is C₁-C₆ alkyl substituted by 1-5 R^(2i) groups, wherein at least one of the R^(2i) groups is —NR⁵C(O)OR⁶, wherein R⁵ is hydrogen and R⁶ is C₁-C₆ alkyl.
 86. The compound of claim 79, or a salt thereof, wherein R^(2f) is C₃-C₈ cycloalkyl substituted by 0-5 R^(2i) groups.
 87. The compound of claim 86, or a salt thereof, wherein R^(2f) is unsubstituted C₃-C₈ cycloalkyl.
 88. The compound of claim 86, or a salt thereof, wherein R^(2f) is C₃-C₈ cycloalkyl substituted by 1-5 R^(2i) groups, wherein each R^(2i) is independently selected from the group consisting of halogen, C₁-C₆ alkyl, C₂-C₆ alkynyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl, wherein the C₁-C₆ alkyl, C₂-C₆ alkynyl, C₆-C₁₄ aryl, and 5- to 10-membered heteroaryl of R^(2i) are substituted by 0-5 groups selected from the group consisting of C₁-C₆ alkyl and C₆-C₁₄ aryl.
 89. The compound of claim 88, or a salt thereof, wherein R^(2f) is C₃-C₆ cycloalkyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is C₁ alkyl.
 90. The compound of claim 88, or a salt thereof, wherein R^(2f) is C₃-C₆ cycloalkyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is C₂ alkynyl substituted by 0-1 phenyl group.
 91. The compound of claim 88, or a salt thereof, wherein R^(2f) is C₃-C₆ cycloalkyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is phenyl substituted by 0-3 C₁-C₆ alkyl groups or is pyrazolyl substituted by 0-3 C₁-C₆ alkyl groups, which C₁-C₆ alkyl groups on phenyl or pyrazolyl of R^(2i) may be the same or different.
 92. The compound of claim 79, or a salt thereof, wherein R^(2f) is 3- to 12-membered heterocyclyl substituted by 0-5 R^(2i) groups.
 93. The compound of claim 92, or a salt thereof, wherein R^(2f) is unsubstituted 3- to 12-membered heterocyclyl.
 94. The compound of claim 92, or a salt thereof, wherein R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein each R^(2i) is independently selected from the group consisting of C₁-C₆ alkyl, C₂-C₆ alkynyl, C₆-C₁₄ aryl, —C(O)R⁵, —C(O)OR⁵, and —S(O)₂R⁵.
 95. The compound of claim 94, or a salt thereof, wherein R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is C₁-C₆ alkyl or C₂-C₆ alkynyl, each of which is substituted by 0-1 phenyl group.
 96. The compound of claim 94, or a salt thereof, wherein R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is C₆-C₁₄ aryl substituted by 0-5 R^(4a) groups, wherein each R^(4a) is independently selected from the group consisting of halogen and C₁-C₆ alkyl.
 97. The compound of claim 94, or a salt thereof, wherein R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is —C(O)R⁵, wherein R⁵ is C₁-C₆ alkyl.
 98. The compound of claim 94, or a salt thereof, wherein R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is —C(O)OR⁵, wherein R⁵ is C₁-C₆ alkyl.
 99. The compound of claim 94, or a salt thereof, wherein R^(2f) is 3- to 12-membered heterocyclyl substituted by 1-5 R^(2i) groups, wherein at least one R^(2i) group is —S(O)₂R⁵, wherein R⁵ is C₁-C₆ alkyl.
 100. The compound of claim 94, or a salt thereof, wherein R^(2f) is 3- to 12-membered heterocyclyl substituted by 2-5 R^(2i) groups, wherein at least one R^(2i) group is —C(O)R⁵, —C(O)OR⁵, or —S(O)₂R⁵, wherein R⁵ is C₁-C₆ alkyl.
 101. The compound of claim 92, or a salt thereof, wherein R^(2f) is azetidinyl, pyrrolidinyl, or tetrahydropyranyl, each of which is optionally substituted by 0-5 R^(2i).
 102. The compound of claim 79, or a salt thereof, wherein R^(2f) is C₆-C₁₄ aryl substituted by 0-5 R^(2i) groups.
 103. The compound of claim 102, or a salt thereof, wherein R^(2f) is unsubstituted C₆-C₁₄ aryl.
 104. The compound of claim 9, or a salt thereof, wherein R² is —NR^(2g)R^(2h).
 105. The compound of claim 104, or a salt thereof, wherein R^(2g) is hydrogen and R^(2h) is C₁-C₆ alkyl substituted by 0-5 halogen.
 106. The compound of claim 104, or a salt thereof, wherein R^(2g) is C₁-C₆ alkyl substituted by 0-5 halogen and R^(2h) is C₁-C₆ alkyl substituted by 0-5 halogen.
 107. The compound of any one of claims 1-106, or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:


108. The compound of any one of claims 1-106, or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:


109. The compound of any one of claims 1-106, or a salt thereof, wherein G is —C(O)R² and R² is selected from the group consisting of:


110. The compound of any one of claims 1-8, or a salt thereof, wherein G is R³.
 111. The compound of claim 110, or a salt thereof, wherein R³ is 5- to 10-membered heteroaryl substituted by 0-5 R^(3e) groups, wherein each R^(3e) group is independently selected from halogen; C₁-C₆ alkyl optionally substituted by halogen; 5- to 10-membered heteroaryl optionally substituted by halogen or C₁-C₆ alkyl; and C₁-C₆ alkoxy.
 112. The compound of claim 110, or a salt thereof, wherein R³ is unsubstituted 5- to 10-membered heteroaryl.
 113. The compound of claim 110, or a salt thereof, wherein R³ is pyrimidinyl or quinazolinyl.
 114. The compound of claim 110, or a salt thereof, wherein R³ is 5- to 10-membered heteroaryl substituted by 1-5 R^(3e) groups, wherein each R^(3e) group is independently selected from halogen, C₁-C₆ alkyl, and C₆-C₁₄ aryl.
 115. The compound of claim 110, or a salt thereof, wherein R³ is 5- to 10-membered heteroaryl substituted by 1-5 R^(3e) groups, wherein at least one R^(3e) group is halogen.
 116. The compound of claim 110, or a salt thereof, wherein R³ is 5- to 10-membered heteroaryl substituted by 1-5 R^(3e) groups, wherein at least one R^(3e) group is C₁-C₄ alkyl.
 117. The compound of claim 110, or a salt thereof, wherein R³ is 5- to 10-membered heteroaryl substituted by 1-5 R^(3e) groups, wherein at least one R^(3e) group is phenyl.
 118. The compound of claim 110, or a salt thereof, wherein R³ is 5- to 10-membered heteroaryl substituted by 2-5 R^(3e) groups, wherein at least one R^(3e) group is C₁-C₆ alkyl, and wherein at least one R^(3e) group is C₆-C₁₄ aryl.
 119. The compound of claim 110, or a salt thereof, wherein G is R³ and R³ is selected from the group consisting of:

S, and, wherein each R^(3e) is independently R⁴.
 120. The compound of claim 110, or a salt thereof, wherein G is R³ and R³ is selected from the group consisting of:


121. The compound of claim 110, or a salt thereof, wherein G is R³ and R³ is selected from the group consisting of:


122. The compound of any one of claims 1-121, or a salt thereof, wherein R² is 5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl optionally substituted by R⁴.
 123. The compound of claim 1, or a salt thereof, wherein the compound is selected from the group consisting of:


124. The compound of claim 1, or a salt thereof, wherein the compound is selected from the group consisting of:


125. A compound selected from one of: Compound Nos. 1-209 in Table 1, or a salt thereof; Compound Nos. 210-329 in Table 2, or a salt thereof; or Compound Nos. 1-329 in Tables 1 and
 2. 126. A compound selected from the group consisting of: N-(2-chloro-3-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(1-methyl-1H-indazole-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(4,4-difluorocyclohexane-1-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-pentanoyl-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(3-fluoro-5-(trifluoromethyl)benzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(3-fluoro-5-(trifluoromethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-pentanoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(4-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-chlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,4-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-chloro-4-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-chloro-5-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-chloro-2-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,5-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-dichlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-chloro-6-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,6-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,5-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,4-dichlorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-picolinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-nicotinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-methyl-1H-indazole-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-2H-indazole-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-2H-indazole-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-methyl-1H-pyrrolo[2,3-b]pyridine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-ethylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-methyl-1H-pyrrolo[2,3-b]pyridine-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-(hydroxymethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinoline-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinoline-7-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinoline-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinoline-8-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-cyclopropylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-isonicotinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-ethylpentanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-chloro-3-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,4-difluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-ethylpentanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-isonicotinoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(3-(thiazol-5-yl)benzoyl)homoserine; N-(3-hydroxy-2-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-(1-methyl-1H-pyrazol-4-yl)benzoyl)-O-(3-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)cyclobutyl)homoserine; N-(3-(1-methyl-1H-pyrazol-4-yl)benzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(2-hydroxy-2-phenylacetyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2-hydroxy-2-phenylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-phenylcyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-2-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-phenylcyclobutane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,2-dimethyl-3-phenylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(tert-butoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(4-fluorophenyl)-2-methylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-methyloxetane-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-hydroxy-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-methoxy-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-2-(pyridin-3-yl)propanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-dihydro-1H-indene-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-cyano-2,2-dimethylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-pivaloyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-dihydro-1H-indene-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((neopentyloxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((1-methylcyclopropoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((1-methylcyclobutoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(((1,1,1-trifluoro-2-methylpropan-2-yl)oxy)carbonyl)homoserine; N-(isopropoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(diethylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(tert-butylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(tert-butyl(methyl)carbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(isopropyl(methyl)carbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(diisopropylcarbamoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,3-dimethylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-methylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-cyclobutylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(1-methylcyclopropyl)acetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-cyclopropylacetyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)-3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((3-methyl-1-(methylsulfonyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-acetyl-3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((3-methylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((cyclohexyloxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(isobutoxycarbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((pyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-(methylsulfonyl)butanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(methyl sulfonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)pyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-acetylpyrrolidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((1-phenylethoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((2-phenylcyclobutoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((3-phenylcyclobutoxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; 2-((tert-butoxycarbonyl)amino)-3-methyl-4-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutoxy)butanoic acid; N-(((2-phenylcyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((4-phenylcyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-acetylazetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-((tert-butoxycarbonyl)amino)propan-2-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-acetamidopropan-2-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclopentyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)cyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(((1-(tert-butoxycarbonyl)-3-(3-chlorophenyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)-3-(4-isopropylphenyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(((1-(tert-butoxycarbonyl)-3-(phenylethynyl)azetidin-3-yl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(tert-butoxycarbonyl)piperidine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,3-difluorocyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-ethyl-4,4-difluorobutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(((2-(phenylethynyl)cyclohexyl)oxy)carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-cyclohexyl-2-methylpropanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(pyridin-2-yl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-ethyl-4,4,4-trifluorobutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-morpholinobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-ethyl-2-phenylbutanoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1H-pyrrolo[3,2-b]pyridine-7-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-cyanotetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(tert-butoxycarbonyl)-3-methylazetidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(tert-butoxycarbonyl)azetidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(methylsulfonyl)piperidine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4,5,6,7-tetrahydro-1H-indazole-7-carbonyl)homoserine; N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl) homoserine; N-(1-methyl-4,5,6,7-tetrahydro-1H-indazole-6-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(1-ethyl-4,4-difluorocyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(6-methylindoline-1-carbonyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-(((tert-butoxycarbonyl)amino)methyl)tetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(pyridin-3-ylmethyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3-chloro-5-methylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(3,5-dichloroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)homoserine; N-(1-(4-(tert-butyl)phenyl)cyclobutane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-methyltetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(4-(trifluoromethyl)tetrahydro-2H-pyran-4-carbonyl)homoserine; N-(3-chloro-5-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,5-dichloroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(bicyclo[2.2.2]octane-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-methyl-1,2,3,4-tetrahydronaphthalene-2-carbonyl)-O-(3-(2(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-((methylsulfonyl)prolyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,4-dimethylnicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-phenyltetrahydro-2H-pyran-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-cyano-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2,4,6-trimethylpyrimidine-5-carbonyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(2,4,6-trimethylnicotinoyl)homoserine; N-(3-chloro-5-fluoroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(isoquinolin-1-yl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(pyridin-2-yl)spiro[3.3]heptane-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(1-methyl-1H-pyrazol-4-yl)tetrahydrofuran-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,4-dimethyl-6-oxo-1,6-dihydropyri dine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4,6-dimethylpyrimidine-5-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,6-dichloro-4-(trifluoromethyl)benzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(2-fluorophenyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(benzo[d][1,3]dioxol-5-yl)cyclohexane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,2-difluoro-1-(m-tolyl)cyclopropane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1-(tetrahydro-2H-pyran-2-yl)cyclopropane-1-carbonyl)homoserine; N-(4-methoxy-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-acetyl-4-(trifluoromethyl)piperidine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2,3-dihydrobenzo[b][1,4]dioxine-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(1-(3-chlorobenzyl)cyclopentane-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(1-(3-(trifluoromethoxy)phenyl)cyclopropane-1-carbonyl)homoserine; N-(4-fluoro-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(2-(tert-butyl)pyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(4-(tert-butyl)pyrimidin-2-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; O-(3-(2-(1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(quinazolin-4-yl)homoserine; N-(6-(tert-butyl)pyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; 2-[(4-amino-2,6-dichloro-benzoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(4-chloro-2,6-dimethylnicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-[(3-chloro-6-methyl-pyridine-2-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(2,6-dimethylpiperidine-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,5-dimethylpyrrolidine-1-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,6-dichloro-4-cyanobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,6-dichloro-3-nitrobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]-2-[(1,2,4-trimethyl-6-oxo-pyridine-3-carbonyl)amino]butanoic acid; N-(2-chloro-4-cyano-6-methylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-bromo-5-chloro-2-fluoroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-N-(5,6,7,8-tetrahydronaphthalene-1-carbonyl)-homoserine; N-(3-bromo-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-[(3-chloro-5-methoxy-pyridine-4-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2,6-dichloro-4-fluoro-benzoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2-chloro-6-fluoro-benzoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(3-bromo-2-chloro-6-fluorobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,4-dimethyl-6-oxo-1-phenyl-1,6-dihydropyridine-3-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(5-bromo-2-hydroxyisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-cyclopropylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-ethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-cyano-2,6-dimethylbenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-bromo-5-fluoroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-methoxy-3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-(trifluoromethyl)isonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-bromo-5-chloroisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-(dimethylamino)-3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-fluoro-2-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2,6-dichloro-3-cyanobenzoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-methyl-5-(trifluoromethyl)isonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(2-hydroxy-3,5-dimethylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-cyano-2-hydroxy-6-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(5-chloro-3-fluoro-2-methylisonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-[(6-methoxy-2,4-dimethyl-pyridine-3-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[2,6-dimethyl-4-[(4-methylpiperazin-1-yl)methyl]benzoyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(3,5-dimethylmorpholine-4-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-[[5-chloro-3-fluoro-2-[(4-methylpiperazin-1-yl)methyl]pyridine-4-carbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; methyl 2-[(7-chloro-5-oxo-2,3-dihydro-1H-indolizine-8-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoate; 2-[(2,6-difluoro-4-hydroxy-benzoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(4-chloro-2-methyl-pyrazole-3-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2-methylpyrazole-3-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-(1-(phenylsulfonyl)piperidine-2-carbonyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-(3,3-dimethylbutanoylamino)-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2-phenylacetyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]-2-[(4,4,4-trifluoro-3,3-dimethyl-butanoyl)amino]butanoic acid; 2-[(4,4-difluoro-3,3-dimethyl-butanoyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[2-phenylpropanoyl]amino]-4-[3- [2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[2-(3,5-difluorophenyl)acetyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[2-(tert-butoxycarbonylamino)-1-methyl-ethoxy]carbonylamino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(3,6-dimethylpyridine-2-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(6-fluorochromane-2-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]-2-[2-[3-(trifluoromethyl)phenyl]butanoylamino]butanoic acid; 2-[(3-chloro-5-methyl-pyridine-4-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(4-cyano-2,6-dimethyl-benzoyl)amino]-4-[3- [2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[4-(2-chlorophenyl)tetrahydropyran-4-carbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(2-hydroxyindane-2-carbonyl)amino]-4-[3- [2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(1-cyclopropylcyclopropanecarbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[3-(difluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridine-6-carbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(1-cyclopropylcyclobutanecarbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[1-(4-isopropylphenyl)cyclopentanecarbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-(bicyclo[2.2.2]octane-4-carbonylamino)-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-(3,4,5,6,7,7a-hexahydro-2H-benzofuran-3a-carbonylamino)-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[1-(2-phenylethyl)cyclopropanecarbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[4-(3-methylisoxazol-5-yl)tetrahydropyran-4-carbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[1-(benzenesulfonyl)cyclopropanecarbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(1-phenylcycloheptanecarbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[(4-methylsulfonyltetrahydropyran-4-carbonyl)amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; 2-[[1-(4-sulfamoylphenyl)cyclopropanecarbonyl]amino]-4-[3-[2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl]cyclobutoxy]butanoic acid; N-((phenylsulfonyl)prolyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(5-chloro-3-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; N-(3-chloro-5-fluoro-2-((4-methylpiperazin-1-yl)methyl)isonicotinoyl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; 2-(pyrimidin-4-ylamino)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic acid; 2-[(3-chloro-5-methyl-pyridine-4-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(2,4-dimethylpyridine-3-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(4-cyano-2,6-dimethyl-benzoyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(3,5-dichloropyridine-4-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; N-(3,5-dimethylmorpholine-4-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2,6-dichlorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(3,5-dimethylisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; 2-[(2,4-dichloro-6-fluoro-benzoyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(2,4-dimethyl-6-oxo-1H-pyridine-3-carbonyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; N-(3-chloro-5-methoxyisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; 2-[(2-chloro-6-fluoro-benzoyl)amino]-4-[4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; N-(tert-butoxycarbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(5-bromo-2-hydroxyisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(3-bromo-5-chloro-2-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2,4-dimethyl-6-oxo-1-phenyl-1,6-dihydropyridine-3-carbonyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-N-(5,6,7,8-tetrahydronaphthalene-1-carbonyl)-homoserine; N-(3-bromo-2,6-dimethylbenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(3-chloro-5-fluoroisonicotinoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(3-bromo-2-chloro-6-fluorobenzoyl)-O-(4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; 2-[(3-chloro-5-methoxy-pyridine-4-carbonyl)amino]-4-[2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]-4-[2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; N-(3-chloro-5-fluoroisonicotinoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2,6-dichlorobenzoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(2-chloro-6-fluorobenzoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; N-(4-fluoro-2-methylnicotinoyl)-O-(2-methyl-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butyl)-homoserine; 2-[(3-chloro-5-fluoro-pyridine-4-carbonyl)amino]-4-[2-hydroxy-4-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)butoxy]butanoic acid; 2-(1-methyl-1H-indazole-4-carboxamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic acid; 2-(3-(1-methyl-1H-pyrazol-4-yl)benzamido)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic acid; 2-(2-chloro-3-fluorobenzamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic acid; 2-(3-(1-methyl-1H-pyrazol-4-yl)benzamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic acid; 2-(2-ethylbutanamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic acid; 2-(1-methyl-1H-indazole-4-carboxamido)-6-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethoxy)hexanoic acid; 2-((tert-butoxycarbonyl)amino)-5-(3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propoxy)pentanoic acid; N-benzoyl-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(quinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(8-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(7-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(7-methylquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(6-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(5-fluoroquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; N-(6-methylquinazolin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)homoserine; and N-(6-(tert-butyl)-2-phenylpyrimidin-4-yl)-O-(3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)cyclobutyl)-homoserine; or a salt thereof.
 127. The compound of claim 1, wherein the compound is represented by any one of the following:

wherein j and k are respectively 2 and 4, 3 and 3, or 4 and 2, or a salt thereof.
 128. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 129. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 130. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 131. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 132. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 133. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 134. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 135. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 136. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 137. The compound of claim 127, wherein the compound is represented by any one of:

or a salt thereof.
 138. The compound of claim 1, wherein the compound is represented by any one of:

wherein j and k are respectively 2 and 4, 3 and 3, or 4 and 2, or a salt thereof.
 139. The compound of claim 138, wherein the compound is represented by:

or a salt thereof.
 140. The compound of claim 138, wherein the compound is represented by any one of:

or a salt thereof.
 141. A pharmaceutical composition comprising a compound of any one of claims 1 to 140, or a salt thereof, and a pharmaceutically acceptable carrier or excipient.
 142. A method of treating a fibrotic disease in an individual in need thereof comprising administering a compound of any one of claims 1 to 140 or a pharmaceutically acceptable salt thereof.
 143. The method of claim 142, wherein the fibrotic disease is pulmonary fibrosis, liver fibrosis, skin fibrosis, cardiac fibrosis, kidney fibrosis, gastrointestinal fibrosis, primary sclerosing cholangitis, or biliary fibrosis.
 144. A kit comprising a compound of any one of claims 1 to 140, or a pharmaceutically acceptable salt thereof.
 145. The kit of claim 144, further comprising instructions for the treatment of a fibrotic disease.
 146. A method of inhibiting αvβ₆ integrin in an individual comprising administering a compound of any one of claims 1 to 140 or a pharmaceutically acceptable salt thereof.
 147. A method of inhibiting TGFβ activation in a cell comprising administering to the cell a compound of any one of claims 1 to 140 or a pharmaceutically acceptable salt thereof.
 148. Use of a compound of any one of claims 1 to 140 or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for the treatment of a fibrotic disease.
 149. A method of modulating at least one integrin in a subject, the at least one integrin comprising an αv subunit, the method comprising administering to the subject an effective amount of: the compound of any one of claims 1-140, or a pharmaceutically acceptable salt thereof.
 150. The method of claim 149, the modulating comprising inhibiting the at least one integrin in the subject.
 151. The method of claim 149, the at least one integrin comprising at least one of avil integrin and αvβ₆ integrin.
 152. The method of claim 149, wherein: the subject has or is at risk of a fibrotic disease selected from the group consisting of: idiopathic pulmonary fibrosis (IPF), interstitial lung disease, radiation-induced pulmonary fibrosis, nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), alcoholic liver disease induced fibrosis, Alport syndrome, primary sclerosing cholangitis (PSC), primary biliary cholangitis, biliary atresia, systemic sclerosis associated interstitial lung disease, scleroderma, diabetic nephropathy, diabetic kidney disease, focal segmental glomerulosclerosis, chronic kidney disease, and Crohn's Disease; and the method comprises inhibiting one or both of αvβ₁ integrin and αvβ₆ integrin in the subject, thereby treating the fibrotic disease in the subject.
 153. The method of any of claims 149 to 152, the subject being in need of treatment for NASH, the effective amount administered to the subject being effective to inhibit at least αvβ₁ integrin, thereby treating the subject for NASH.
 154. The method of any of claims 149 to 152, the subject being in need of treatment for IPF, the effective amount administered to the subject being effective to inhibit at least αvβ₆ integrin, thereby treating the subject for IPF.
 155. The method of any of claims 149 to 152, the subject being in need of treatment for PSC, the effective amount administered to the subject being effective to inhibit at least one of αvβ₁ integrin and αvβ6 integrin, thereby treating the subject for PSC.
 156. A method of modulating TGFβ activation in a cell, comprising contacting the cell with: the compound of any one of claims 1-140, or a pharmaceutically acceptable salt thereof; or the pharmaceutical composition of claim
 141. 157. The method of claim 156, the modulating comprising inhibiting TGFβ activation in the cell.
 158. The method of claim 156, the TGFβ activation being mediated in the cell by at least one of αvβ₁ integrin and αvβ₆ integrin.
 159. A method of treating a subject in need thereof, comprising: administering to the subject a therapeutically effective amount of the compound of any one of claims 1-140, or a pharmaceutically acceptable salt thereof, wherein the subject has at least one tissue in need of therapy and the tissue has at least one elevated level of: TGFβ activation and/or expression; αvβ₁ integrin activity and/or expression; or αvβ₆ integrin activity and/or expression; wherein the at least one elevated level is elevated compared to a healthy state of the tissue.
 160. The method of claim 159, wherein the method selectively inhibits αvβ₁ integrin compared to αvβ₆ integrin in the subject.
 161. The method of claim 159, wherein the method selectively inhibits αvβ₆ integrin compared to αvβ₁ integrin in the subject.
 162. The method of claim 159, wherein the method inhibits both of αvβ₁ integrin and αvβ₆ integrin in the subject.
 163. The method of claim 159, wherein the method selectively inhibits both αvβ₁ integrin and αvβ₆ integrin compared to at least one other αv-containing integrin in the subject.
 164. The method of claim 159, wherein the αvβ₁ integrin is inhibited in one or more fibroblasts in the subject.
 165. The method of claim 159, wherein the αvβ₆ integrin is inhibited in one or more epithelial cells in the subject.
 166. The method of claim 159, wherein the at least one tissue in the subject comprises one or more of: lung tissue, liver tissue, skin tissue, cardiac tissue, kidney tissue, gastrointestinal tissue, gall bladder tissue, and bile duct tissue. 